
Copyriglit]^" 



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CQEiiRiGia' D£Posm 



Published under Supervision of 

A. Eugene Michel and Staff, 

Advertising Engineers, New York, 

and printed by 
Franklin Printing Co., Philadelphia 



STEAM HEATING 



■A Manual of Practical Data 

Compiled by 
THE GENERAL ENGINEERING COMMITTEE 

OF 

WARREN ^YEBSTER & COMPANY 



Published by 

WARREN WERSTER & COMPANY 

CAMDEN, N. J. 

First Edition, Revised. May, 1922 
Copyrighted 1922 by Warren Webster & Company 

Price $3.25 Net 






FOREWORD 

THE subject of Heating and Ventilation has been covered broadly in 
many handbooks that are available for reference, but there has been 
a demand also for a book of information confined exclusively to Steam 
Heating and covering that field in all necessary detail. 

Steam Heating is therefore the one topic of this volume and the editors 
have aimed to cover the subject with comprehensive data, arranged in such 
convenient and useful form as will best meet the needs of technical men in 
the engineering and contracting fields. 

The information given is authentic, being based upon actual practice 
and largely upon the experience of Warren Webster & Company, who, as 
pioneers, have specialized for more than thirty years in the effective use of 
steam for all heating purposes. Many of the designs and methods originated 
by this firm are now the recognized service standards. 

Special articles and helpful suggestions have been contributed by John 
A. Serrell, by the General Engineering Committee, and by John B. Dobson, 
Ralph T. Coe, William Roebuck, Russell G. Brown, Harry E. Gerrish, 
Howard H. Fielding, George A. Eagan, E. K. Lanning and other members 
of the Webster organization. 

"Steam Heating" offers the best thought of this organization, and as 
part of Webster Service, it is intended to be of real value throughout the pro- 
fession. The observance of good judgment and painstaking care in following 
its teachings will do much toward obtaining creditable and satisfactory 
results. 

If further explanations, additional information or helpful co-operation 
are desired, the Engineers and Service Men in the branch offices of Warren 
Webster & Company throughout the country are always available for 
consultation and assistance. 

CAMDEN, NEW JERSEY ^ WARREN WEBSTER & COMPANY 

JANUARY 1, 1922 



General EiNgineering Committee 



OF 



Warren Webster & Company 

William M. Treadwell, Chairman 
John A. Serrell, Advisory Engineer 

WiUiam F. Bilyeu J. Logan Fitts Harry M. Miller 

Charles F. Eveleth Sidney E. Fenstermacher Rudolph G. Rosenbach 

4 

©CI.A674256 
nM 23 !922 



CONTENTS 

PART L— STEAM HEATING 

PAGE 

Chapter I. — Elements of Steam Heating 9 

Chapter H. — Data Required for Steam Heating- 
System Design 15 

Topography 15 

Location and character of soui'ce of heat 15 

Exposiu'e and protective conditions 15 

Outside temperatures 16 

Floor plans, elevations and cross-sections 18 

Inside temperature requirements 18 

Contents and use of enclosure 19 

Chai-acter and location of heating surface 19 

Location of supply and retm'n lines 20 

Chapter HI. — Heat Transmission 21 

Chapter IV. — Air Infiltration 31 

Chapter V. — Method of Calculating Heat Requirements 34 

Chapter VI. — Method of Computing and Selecting Heating Surface. . . 42 
Chapter VII. — Ventilation Problems as They Affect the Design of Heat- 
ing Systems 59 

The fu-eplace 60 

Dii-ect-indirect system of heating and ventilation 60 

Indkect system of gravity ventilation 60 

School buildings 61 

Theatres and auditoriums; churches 63 

Banquet halls, dining rooms, meeting halls, etc 64 

Exhaust ventilation of industrial plants 65 

Hot blast systems of heating for industrial plants 66 

Factors entering design of complete heating and ventilating plant 67 

Air quantities required for ventilation 67 

Sizing of the ducts 68 

Calculation of resistance or pressure 69 

Selecting the apparatus ^. . 72 

Size and arrangement of fans; heaters 72 

Boiler horsepower requu-ed 73 

Chapter VIII. — Proportioning of Chimneys 74 

Chimneys for house-heating boilers 74 

Chimneys and draft for power boilers 78 

Draft 78 

Draft formula 79 

Draft losses and loss in stack 80 

Height and diameter of stacks 81 

Losses in flues 83 

Loss in boilers and in the furnace 84 

Draft required for different fuels 85 

Bate of combustion 85 

Solution of a problem 86 

Correction in stack sizes for altitudes 87 

5 



Chapter IX.— Boilers 89 

Chapter X. — Selection of the Proper Type of Steam Heating System . . 95 

Size and type of building 97 

Residences 97 

Apartment buildings 97 

Store and office buildings 97 

Public buildings 98 

Use of building, ._ 100 

Location of building and topography of site 101 

Construction and architectural features 103 

Sources of steam supply 103 

Operation and attention 107 

Chapter XI. — Flow of Low-pressure Steam Through Piping 110 

Flow of steam through pipes 110 

Friction in run Ill 

Condensation loss 113 

Effect of deflection, contraction and expansion 113 

Pressure drop 114 

Modulation systems 116 

Vacuum systems 120 

Sizing of piping 123 

Vacuum system 123 

Condensation allowances 124 

Pressure drop for initial velocity 125 

Modulation system 127 

Chapter XII. — Critical Velocities in Radiator Run-Outs 132 

Chapter XIII. — Vacuum Pumps and Auxiliary Equipment 137 

Proportioning of steam end of reciprocating vacuum pump 143 

Power-driven reciprocating vacuum pumps 143 

Disposal of vacuum pump discharge 144 

To waste 144 

To air-separating tanks 144 

To open vent tanks 145 

To hydro-pneumatic tanks 147 

To loop seal on tank outlet to heater or boiler 148 

To receiver and boiler-feed or tank pump 148 

Dry-vacuum pump receiver and water pump 150 

Suction strainers 151 

Vacuum governors 151 

Chapter XIV. — Laboratory Tests of Return Traps 153 

Tests for heating efficiency 154 

PART II.— WEBSTER SYSTEM SPECIALTIES AND APPLICATIONS 

Chapter XV. — Webster Systems of Steam Heating 161 

Webster Modulation Systems 161 

Boilers operating up to 10-lb. pressure 162 

Boiler pressure from 10-to 50-lb 163 

Street system carrying any pressure 164 

6 



Chapter XV. — Continued 

Webster Vacuum Systems 165 

With power boilers 165 

Dripping supply mains and risers 167 

Radiator cormections 169 

Disposal of the products of condensation 170 

The vacuum pump 170 

Final disposal of the condensation 171 

Ventilation problems 172 

With medium-pressm'e boilers 172 

With low-pressiu-e boilers 173 

Steam furnished from street system 173 

Special modifications 173 

Webster Conserving System 173 

Webster Hylo Vacuum System 176 

Chapter XVI. — Applications of the Webster System to Lumber and 

Other Kiln-Drying Problems 179 

Chapter XVII. — Apphcations of the Webster System to Slashers and 

to Cloth and Paper Drying Apparatus 188 

Cloth and warp drying machines 190 

Paper machines 192 

Chapter XVIII. — Apphcations of the Webster System to Railroad 

Terminals and Steamship Piers 194 

Chapter XIX. — Applications of the Webster System to Vacuum Pans 

and Similar Apparatus 196 

Chapter XX. — Applications of the Webster System to Sterilizers, 

Cooking Kettles and Similar Apparatus 202 

Hospital equipment 202 

Cooking kettles, plate warmers, bain-maries, coffee m-ns and other kitchen 

equipment 204 

Chapter XXI. — Applications of the Webster System to Greenhouses . . 205 

Chapter XXII. — Installation Details 215 

For Webster Vacuum System and Webster Modulation System 215 

For Webster Vacuum System only 222 

For Webster Modulation System only 228 

Chapter XXIII. — Capacities and Ratings of Webster Valves and Traps 233 

Modulation Supply Valves 234 

Return Traps 237 

Selection of Modulation Supply Valves and Return Traps 238 

Heavy-duty Return Traps 239 

Series 20 Modulation Vent Traps 239 

Modulation Vent Valves 240 

Chapter XXIV. — Appliances for Webster Systems of Steam Heating 241 

Return traps 241 

Sylphon Trap 242 

No. 7 Trap 246 

7 



Chapter XXIV. — Continued 

Heavv-duty Trap, standard and high-differential types 247 

Type W Modulation Valve 250 

Double-service "\^alve 252 

Oil Separators ' 254 

Low-pressure Receiver Oil Separators 257 

Grease and Oil Traps 257 

Suction Strainer 258 

Dirt. Strainers 259 

Vacuum-pump Governor 260 

Suction Strainer and Vapor Economizer 261 

Lift Fittings, Series 20 .^ 263 

Receiving Tanks 264 

Water Accumulator 267 

Gauges for Webster Systems 267 

Modulation Vent Trap 268 

Modulation Vent Valve 270 

Damper Regulator 271 

Hylo Vacuum-control Sets 272 

Sylphon Conserving Valve 273 

Low-pressure Roller Feeder, Series 16 274 

High-pressure Sylphon Trap 275 

Hydro-pneumatic Tanks 276 

Expansion Joints 278 

Steam Separators, Series 21 283 

Chapter XXV. — Specifications for Webster Systems 286 

A^acuum System 286 

Modulation System 289 

Chapter XXVI. — Webster Sylphon Trap Attachments 293 

For Sylphonizing Webster Traps of eeu'lier types 293 

No. 422 Webster Thermostatic Valves 294 

Webster Motor Valves 294 

No. 422 Webster Water-seal Motors 294 

No. 522 Water-seal Traps 295 

Multiple-unit Webster Valves of eai'lier types 296 

For Sylphonizing radiator outlet valves of other makes 297 

Chapter XXVII. — Fuel Saving by Preheating Boiler-feed Water ..... 301 

Webster Feed-water Heaters 302 

Standai'd Type 304 

Preference Cut-out Heater 308 

The Webster-Lea Heater Meter 313 

PART III.— ADDENDA 

Chapter XXVIII. — Miscellaneous Useful Information 315 

For lists of illustrations and tables, and detailed index, see back of book (Page 354). 



NOTE. — For convenient reference, each table, illustration and formula 
is given a compound number, the first part of which indicates the chapter 
and the second the sequence in that chapter. Example: Table 3-6 indi- 
cates the sixth table in Chapter 3. 



T 



Part I— Steam Heating 

CHAPTER I 

Elements of Steam Heating 

HE purpose of a heating system is to warm the interior of a structure 

to a desired degree of temperature and to maintain this condition 

against a lower exterior degree. It is usual to assume the exterior 
temperature to be the average minimum expected in the locality. 

To warm the interior and to maintain a given temperature, heat is 
required to replace thau which is absorbed by the contents and that trans- 
mitted tlu'ough the structure to the exterior. 

The unit measure of heat in English-speaking countries is the British 
thermal unit, which is the heat necessary to raise the temperature of one 
pound of water from 59 to 60 deg. fahr. This is commonly known as B.t.u., 
or heat unit. 

The quantity of heat required to raise the temperature of a given 
weight of a substance through one deg. fahr. as compared with the quantity 
of heat required to raise the same weight of water from 62 deg. to 63 deg. 
fahr. is called the specific heat of that substance. 

The heat content, or quantity of heat per degree of a given mass of a 
substance, is the product of its specific heat and its weight in pounds. 

The rate at which initial heat is required to raise the temperature of a 
cold structure and its contents to the desired degree in a given time may 
be much greater than that n,ecessary to maintain the required temperature 
after initial heating, or warming up, has been accomplished. 

The greater the length of time permitted for initial warming, the less 
difference there will be between the heat requirement per unit of time during 
initial heating and that required during subsequent maintenance. 

Heat losses by transmission tlirough various forms of building structure 
have been ascertained with more or less accuracy, and much information on 
this subject has been published from time to time. These data are being 
constantly improved as new forms of construction appear. 

The principal discrepancies between published data on transmission are 
probably due mainly to various allowances which have been included for 
infiltration. Infiltration, or air leakage, should be considered indei^endently 
of structural transmission. 

Local differences in workmanship and material of structure, as well as 
errors in obserA^ation, have further contributed to discrepancies, and in 
many instances the results of tests observed at one temperature difference 
have been reduced by direct proportion to a " per-degree-difference " basis. 

Until recently it has not been generally recognized that this last-men- 
tioned basis is in error, in that it is likely to give too high a rate of heat loss 
for smaller temperature difference and too low a rate for larger temperature 
difference than that existing during the test. 

9 



The heat transmission factors in Chapter 3 are based upon experience 
Avith various substances used in construction under average conditions at a 
difference of 70 deg. fahr. between interior and exterior temperatures. 
Factors for other temperature differences are stated as percentages of the 70 
deg. normal. The effects of exposure and of varying wind velocities are 
separately considered as losses due to infiltration. 

In order to determine the amount of heat required it is necessary to 
know or establish : 

First: The lowest temperature to which the interior will fall, that is, 
the "initial" temperature; and the temperature which it is desired shall be 
maintained within the enclosure, or the "maintained" temperature; 

Second: The time period in which it is required that the structure and 
its contents must be raised from initial to maintained temperature; 

Third: The nature and the weight of the building and its contents 
(especially if large quantities of glass, metal or water are included) ; 

Fourth: The minimum exterior temperature; 

Fifth: The direction and anticipated velocities of prevailing cold winds; 

Sixth: The construction of the enclosure ; 

Seventh: The topography of the site, and other local peculiarities. 

The heat transmitted hourly through the structure at a temperature 
difference between maintained interior and minimum exterior temperatures, 
plus the heat required to warm the infiltrated air through the same difference 
of temperature, gives the hourly maximum heat requirement during main- 
tenance. In Chapters 3 and 4 these two causes for heat requirements are 
further discussed. 

During initial heating or "warming up," heat units in addition to those 
required for maintenance must be supplied to raise the temperature of the 
structure and its contents of air and stored materials from their initial 
temperature to the desired temperature. 

In practice the heat absorbed by the structure and its stored materials 
is usually neglected, as the error is small. However, if the interior walls or 
columns are massive, or if the contents of the building include large quan- 
tities of materials with high specific heats, such as iron, steel, water, glass, 
etc., the heat which is absorbed by these must be taken into account. 

In almost all cases the heat required to raise the air contents of the 
enclosure from the initial to the maintained temperature must be considered. 

After determining the amount of heat required to warm the various 
substances during initial heating, the lioiu"ly rate at which this additional 
heat must be supplied during initial heating is obtained by multiplying this 
heat quantity by the reciprocal of the warming-up period in hours. 

Applications of the problem of determining the heat requirements will 
be found in Chapter 5. 

Where the heating requirements for warming-up are large compared 
with those for maintenance, the radiation necessary for the warming-up 
requirements and consequently the heat emitted will be correspondingly 
excessive during maintenance. It is often advisable to increase the length 
of the warming-up period first allowed in order to reduce this excess radiation. 

10 



Overheating after the initial warming-up period, may be avoided by the 
manipulation of the hand-controlled inlet valves on the radiators or by a 
system of automatic temperature control. 

Having estimated the total hourly heat requirement, the next consider- 
ation is the proper proportioning and distribution of radiating surfaces 
throughout the enclosure, for obtaining the desired heating effect from the 
circulation of a fluid of higher temperature. 

In the following chapters the fluid considered for conveying heat is 
steam at pressures slightly above that of the atmosphere. The high thermal 
value, or B.t.u., per pound of steam and the convenience with which it can 
be utilized by means of commercial boilers, radiating surfaces, pipe and fit- 
tings and the special apparatus of the Webster Systems, have demonstrated 
the superiority of steam at low initial pressures for the great majority of 
installations. 

The radiating surfaces, or radiation, normally used in low-pressure 
steam heating to transmit heat from steam to the enclosure to be warmed, 
are of two general classes. Direct and Indirect, each of which has many 
specific sub-divisions. 

Direct radiation, properly classified, comprises only those arrangements 
of radiating surface which are located directly in the space to be heated. 

Radiation which is not wholly exposed in the space to be heated is 
termed indirect radiation. Units which are concealed under window boxes, 
or in housings having an air inlet near the floor line and a heated air outlet 
above the radiation, or which are enclosed in casings outside of the space 
to be heated and which have a cool-air inlet from any source and a warm- 
air connection to convey by heated air the necessary heat units to the 
space to be heated, are examples of this type of radiation. 

Originally the circulation of air for indirect heating by the method last 
mentioned was induced entirely by the difference in weight of the air columns 
before and after coming into contact with the enclosed radiating surface. 
Present usage designates such surfaces as gravity indirect, distinguishing 
them from surfaces used in the later development, where additional circu- 
lating velocity is imparted mechanically by a fan or blower. Where mechan- 
ical means are used these surfaces are now designated as mechanical indirect 
or blast surfaces. 

Certain forms of radiating surfaces exposed in a room and so arranged 
with dampers and ducts that air wholly from the room or partly from 
without may be used to convey heat from the surface of the radiator to the 
room, are called direct-indirect surfaces. 

The rate of heat transmission through radiating surfaces from a given 
interior to a given exterior temperature varies not only with all classes of 
radiation but w ith all sub-divisions of those classes. This is due mainly to 
variation in convection, that is, in the facility for absorption of heat from 
the outer surface into the surrounding medium, and, in a lesser degree, to the 
dispersion of radiant heat. So great is this variation that, under similar 
conditions of location and temperature difference, and even in the simplest 
form of direct radiation, a low, narrow radiator gives off 40 per cent more 
heat per square foot of radiation than one that is extremely high and w ide. 
I 11 



The term "square feet of radiation," therefore, means nothing specific 
and should not he used indiscriminately for sizing boilers, mains or other 
apparatus in the heating system. 

The radiating surface for the local conditions, heat requirements 
and architecture, having been selected and located, the proper size of 
radiating units should be determined. For this purpose the information on 
heat emission of various types of radiation. Chapter 6, will be found useful. 

The pipes which convey the heating fluid from its soiu-ce to the radiating 
surfaces are termed suj^ply mains. Those conveying the products of con- 
densation from the radiating surfaces to the point of disposal are termed 
return mains. The vertical parts of these mains are usually called risers, 
to distinguish them from horizontal runs. Risers, in turn, are classified by 
their direction of flow, as up-feed or down-feed risers. The small branches to 
individual units of radiation are known as run-outs ; those supplying several 
units as branches, and those conveying all of the heating medium are usually 
termed trunk mains. 

The flow of the heat-carrying medium is always toward a lower pressure, 
and if the medium is steam confined in pipes or ducts sealed from the atmos- 
phere, the arbitrary dividing line conventionally drawn between pressure 
and vacuum does not enter. The problem involves only heat content, 
density, difference in pressure, condensation and friction. 

If the lowest terminal pressure in the system is that of the atmosphere 
as in an open-return line or modulation system, the initial pressure must be 
somewhat above that of the atmosphere. The amount of pressiu'e above 
atmospheric depends largely upon the friction which must be overcome 
in the piping and upon the pressure necessary to give the steam its initial 
velocity. If, however, a terminal pressure lower than that of the atmosphere 
is mechanically maintained, as in vacuum systems, the initial pressure may 
be above, at or below that of the atmosphere as best meets the local 
conditions. 

Vacuum system practice, with few exceptions, demands that a steam 
pressure at least equal to that of the atmosphere be maintained in the run- 
outs most distant from the source of steam suj^ply, in order to avoid the in- 
leakage of air that would otherwise probably occur through minute leaks. 
This terminal pressure requires an initial pressure higher in some degree 
than that of the atmosphere. Local conditions, such as source of supply, 
length and character of pipe run, and use and permanency of the plant, 
make the selection of pressure difference one of good engineering judgment 
rather than the application of any fixed rule. The proper basis for propor- 
tioning the supply system is dealt with in Chapter 11. 

The primary function of return mains is the removal and disposal of 
the products of condensation. These mains should provide gravity flow 
wherever possible. Pressure difference should be used to stimulate flow only 
where gravity alone is not practical. 

The products to be removed consist of water, air. vapor, gases from 
impurities and last, but not to be overlooked, dirt and foreign matter. 

The last consists of initial impurities such as core-sand, gravel, chips, 
mill scale, grease, etc., left in the heating system Avhen erected, together 

12 



with rust particles and scale from impure feed water. Were it not for the 
dirt which collects and the uncertainty as to its volume, return mains 
might be made much smaller. 

Formulae and tables of capacities of straight, smooth pipes laid on even 
grades for return of condensation, and tables of accepted capacities com- 
pensating for uncertainties of grade and dirt are given in Chapter 11. 

The hot distilled water should be returned to the boiler wherever pos- 
sible. The saving due to the heat content of this Avater and its freedom 
from scale-forming and other impurities, warrants considerable initial out- 
lay in retm-n apparatus. 

No specific type of return apparatus will best fit all conditions. The 
single low-pressure heating boiler may have its water line so located that 
the water of condensation will flow back into the boiler by gravity against 
the highest steam pressure carried. Between this simple case and a modern 
high-pressure central generating plant, where part of the exhaust steam is 
used as a by-product for heating purposes in an extended group of build- 
ings, there is a wide range of conditions. The selection of the best combi- 
nation of return apparatus for the individual plant is therefore dependent 
upon comprehensive practical experience. 

Some of the possible combinations of return apparatus are described 
and shown in typical diagrams in Chapter 13, and basic rules are given for 
estimating proper sized apparatus. However, it is manifest that discussion 
in this volume cannot cover all requirements, and in this, as in the selection 
of all apparatus for special conditions, it is recommended that specific 
engineering advice be obtained from the home office or a nearby branch 
of the manufacturer, before a selection is made. 



i;i 




3 



P. 

a 



i 






14 



CHAPTER II 

Basic Data Required for Design of a 
Steam Heating System 

INTELLIGENT design of any heating system in either new or existing 
buildings requires that certain basic data shall be available. For exist- 
ing buildings the present use of which will continue, it is usually possible 
to obtain quite definite data to work upon. If plans are the available in- 
formation, much of the necessary data must be based upon assumptions of 
probable conditions. 

In any event, good judgment, preferably founded upon ripe experience, 
must play its equal part with scientific knowledge in the final application 
of the data obtained. 

Topography: The design of an efficient heating system, especially 
where a group of buildings is being considered, requires that a careful study 
be made of the grade levels of the different buildings, each one to the other, 
so that, if possible, the condensation from the heating surfaces may flow 
by gravity to a central point from which it may be returned to the source 
of steam supply. 

In cases where the conditions are such that the condensate will not 
flow by gravity to a central point, special methods for lifting the con- 
densate to a higher level are necessary as described hereafter. 

Location and Character of Source of Heat: It follows from the 
above that wherever possible the source of steam supply should be located 
at a lower level than that of the buildings to be heated. 

In a plant consisting of a group of buildings there is usually a power 
generating plant, the by-product from which, in the form of exhaust steam, 
should be utilized to the fullest extent in the heating of the buildings. The 
economies incident to the use of this exhaust steam as a by-product 
frequently determine the adoption of an isolated power generating plant 
rather than the purchase of power from outside sources and the installation 
of a boiler plant for heating purposes only. 

Exposure and Protective Conditions: By exposure is meant the 
relation of the outside surfaces of the building or buildings to the prevailing 
cold winds of winter, which by their pressure cause infiltration of excess 
quantities of cold air and the rapid removal of heat from the outside surfaces 
of the structure. To ofl^set this, a larger amount of radiation must be 
provided on the sides having greatest exposure, than for sides more favorably 
located with the protection of surrounding buildings or hills. 

Consequently the designer should determine the direction of the pre- 
vailing winter winds and their probable velocities and duration as well as the 
topographic features which may afford protection. 

15 




r3i l~] r 131 

16 21 26 31 5 10 15 20 25 30 5 10 15 20 25 30 4 9 14 19 24 29 3 



r 1 T"" T" i I 1 13"! 

B 13 18 23 28 5 10 15 20 25 30 4 9 14 19 




3i| I M I Fil I I I 1 T I I I Mill I 

16 21 26 31 5 10 15 20 25 30 5 10 15 20 25 30 4 9 14 19 24 29 3 8 1 3 18 23 28 5 10 15 20 25 30 4 9 14 19 

Fig. 2-2. Daily maximum and minimum temperatures in New York City during the heating seasons of 

1916-1917 and 1917-1918, (on opposite page) 1918-1919 and 1919-1920. Based upon 

United States Weather Bureau Reports. 

Outside Temperatures: Although the records of the United States 
Weather Bureau (See Figure 2-1) may show an extreme minimum tempera- 
ture much lower than that usually experienced in a given locahty, it is not 
customary to estimate heating requirements with that extreme tempera- 
ture as a basis. 

Generally, the average minimum temperature, obtained from United 
States Weather Bureau records over a period of ten years or longer, is the 
fundamental consideration. To illustrate the necessity for considering a 
period of years, rather than to establish the basis on the result of two or 
three years, charts (Figure 2-2) have been prepared showing the minimum 




. . I I I i I T I I I l3lM I ^1| I I I 29| I I |3, . , 

16 31 26 31 5 10 15 20 25 30 5 10 15 20 25 30 4 9 14 19 24 29 3 a 13 18 23 28 4 9 14 19 24 29 3 8 13 18 



and maximum temperatures for each dav of the heating season for the 
winter months of 1916-1917 to 1919-1920 for New York City. 

These charts show the extreme variation of minimum temperature 
for different winters and indicate that a safe average cannot be obtained 
without having records of a long period of years for consideration. They 
are shown also as a suggested form for the preparation of similar data from 
Weather Bureau reports for any locality where it is desired to study the 
temperature conditions upon which the design of a heating system is to 
be based. 

It is possible to operate the most effective types of steam heating 
systems with a slight increase in steam pressure, which results in an 
increased rate of heat emission from the radiating surfaces. This flexi- 
bility is advantageous during short periods of very cold weather. 



17 



Floor Plans, Elevations and Cross-Sections : To properly design 
the heating system for one or more buildings, complete floor plans and suffi- 
cient elevations and cross-sections, showing details of construction, materials, 
etc., must be available for accurately calculating the heating requirements. 

In designing heating systems for existing buildings, accurate data may 
be obtained by survey, but with designs of new buildings certain assump- 
tions are necessary. These may or may not be justified when construction 
is complete. A frequent element of error lies in change from original plans 
without proper consideration for the effect upon the heating system. 

These possible discrepancies in construction and deviation in design 
from original j^lans make it quite necessary for the designer of the heating 
system to place himself on record as to the basic factors of his calculation. 

Inside Temperature Requirements: The temperature to be main- 
tained and the lowest permissible temperature, are usually governed by the 
use for which the enclosure is intended. 

Inside temperatures are usually determined at the breathing line and 
not closer than 5 ft. from the most exposed wall. 

The important considerations for decision lie in the following questions: 

Is the heat to be maintained continuously 24 hours per day or for stated 
portions of the total 2^i hours? 

If intermittent heating, how tong a time may be alloived to raise the 
room temperature to the required maintained temperature? 

Through how long a period will heat be shut off and how low may 
the room temperature become during this closed down period? 

The following table indicates the usual range in maintained tempera- 
tures desired for various classes of occupancy, but it should be kept in mind 
that temperature is largely a matter of individual preference so that such a 
table can be considered only as a guide in the final selection. 

Table 2-1. Temperature for Various Rooms in Deg. Fahr. 

Bath rooms 75 to 85 

Churches 60 to 70 

Entrance halls to public buildings 50 to 60 

Factories 60 to 70 

Foundries 50 to 60 

Gymnasiums 60 to 65 

Homes for aged 80 

Hospitals 72 to 75 

Lecture halls 60 to 70 

Living rooms 68 to 72 

Machine shops 60 to 70 

Offices 68 to 72 

Operating rooms 70 to 90 

Paint shops 80 to 90 

Prisons, day confinement 60 to 65 

Prisons, night confinement 50 to 55 

Public buildings 68 to 72 

Schools 70 

Shops (stores) 50 to 65 

Swimming halls 70 to 75 

Vestibules for stores and office buildings 70 to 80 

18 



The relative humidity of the atmosphere which is hkely to exist in any 
room or building has a bearing upon the desirable inside temperature. 

For a living apartment, a normal temperature of 70 deg. fahr. and rela- 
tive humidity of 50 per cent (about 4 grains of water vapor per cubic foot of 
content) is considered by most authorities to be a very satisfactory condition 
of the air. If the temperature is lower than 70 deg., the relative humidity 
should be higher than 50 per cent or if the temperature is higher, the relative 
humidity should be lower if the same effect of comfort to the occupant is to 
result. 

It is usual, however, that the relative humidity is found to be much less 
than 50 per cent in living apartments heated to 70 deg. fahr. and has been 
observed to be as low as 28 per cent. With very low relative humidity the 
effect upon the occupant is a feeling of chilliness even though the temperature 
may be increased to 78 or 80 deg. falu". This cooling effect is due to the 
rapid evaporation of moisture from the occupant's skin, which is brought 
about by the low vapor pressure of the atmosphere. Conversely, where 
extremely high relative humidity exists, a temperature of 70 deg. fahr. 
might feel oppressively hot to the occupant. 

Contents and Use of Enclosure : A very important consideration 
for the designer is that of the materials and machinery within the enclosure, 
and their capacities for absorbing heat. This has an important bearing 
upon the permissible time limit for warming up. 

Large quantities of material or machinery having a high heat content 
will prolong the time for warming and will have an opposite effect of re- 
tarding the loss of temperature when the heat supply is cut off. 

For consideration of this factor, the designer should have details of the 
weight and substance of each of the various items of machinery and materials. 
With this data and a table of specific heats of substances such as on pages 
342-3, the total heat contents or heat-absorbing capacities which influence 
the warming-up period can be determined. 

Likewise, the designer should determine the total heat given off by the 
operation of the machinery, motors, lights, etc., although this is not of so 
much importance in buildings where the temperature requirements are those 
to be maintained during periods when machines, etc., are not in operation. 

In schools, theaters, auditoriums, churches, etc., where large numbers 
of persons may gather, it is necessary to allow for the heat given off by the 
human bodies if overheating is to be prevented. In such cases, ventilation 
is usually required to remove the bodily heat with its excessive humidity. 

In manufacturing plants, portions of buildings often require unusual 
quantities of heat to warm the large amounts of air which replace that drawn 
from the rooms through exliausting fans on grinders, dryers and similar 
apparatus. This condition requires a careful investigation of the factors 
involved in the unusual rate of air change. 

Character and Location of Heating Surfaces: The selection of 
the radiation from a choice of direct, indirect, direct-indirect or blast type 
depends largely upon the use for which the enclosure is intended, the ven- 

19 



tilation requirements, the local building laws, school and labor codes, and 
other general considerations. 

Whether pipe coils, cast-iron wall radiation or column cast-iron radi- 
ators are to be used for direct heating is usually a question of availability 
of materials, cost of installation and the esthetic effect required. 

The selection of the type and location of the different radiating units 
may best be determined by a study of the plans and elevations of the build- 
ing to be heated. 

Location of Supply and Return Lines : In installations of the type 
for hotels, hospitals, office buildings or other public buildings with finished or 
decorated walls it is customary to conceal the steam and return risers, and their 
run-outs to radiators, in the wall and floor construction. In factory instal- 
lations and other less expensive types of construction these lines are exposed 
and in many instances they are used as prime radiating surfaces. 

In cases where the outlets from the risers are taken below the level of 
entrance to the radiators it is essential that the run-outs shall be so graded 
that the condensation will flow back by gravity into the risers regardless of 
the maximum velocity of steam which may flow in the opposite direction. 
It is therefore of prime importance that the maximum velocity shall be kept 
well below that at which the condensation will be swept along with the steam. 
This important feature of design is discussed in further detail in Chapter 12. 

A down-feed system of supply is preferable wherever building conditions 
will permit, since the condensation will then flow in the same direction and 
will be assisted by the flow of steam as well as by gravity. This permits the 
use of smaller supply risers and run-outs due to the higher velocities of 
steam flow which are permissible. 

Return run-outs, risers and mains must grade in the direction of flow of 
condensation to some low point or points from which the condensation will 
be returned to the source of steam supply or other point of disposal. 



20 



CHAPTER III 

Heat Transmission 

THE same principle of transmission of heat from a higher to a lower 
temperature that makes steam heating effective, also functions in the 

transmission of heat through materials of construction to make such 
heating necessary. 

Heat seeks equilibrium, and consequently there is a transfer of heat 
from a higher to a lower temperature with greater or less rapidity, depending 
upon the difference in temperature and the character and thickness of the 
material through which it flows. 

For the purpose of estimating the heat losses from enclosures, numerous 
tests and deductions from practice have been made to determine the rate 
of heat transmission through the various types and materials of surfaces 
used for enclosing space. So many variables enter this problem that it is 
impossible to predict the heat transmission exactly unless all of the peculiari- 
ties of any case under consideration have been previously determined. 

Tables of heat transmission, therefore, attempt to provide for average 
conditions of construction of the enclosing substances. Due regard must 
be given to the facility with which heat is absorbed and removed from the 
surfaces of the enclosing substances, and to the heat which is transmitted 
through them, due to the difference between the temperatures existing at 
their surfaces, which may be termed "heat head." 

This heat head has been considered in many formulae as a constant 
increase per degree of temperature difference. As the result of tests with 
the same substance under various temperature differences this deduction 
has been proved to be incorrect. Higher temperature differences cause 
greater transmission per degree difference than lower temperature differences. 

The probable variation in heat transfer under various conditions of 
heat head is shown in Fig. 3-1. The rate of transfer for any difference 
between inside and outside temperatures other than 70 deg. is expressed 
as a percentage of that at 70 deg. difference. 

The discussion of Rates of Heat Transmission in this book recognizes 
the following fundamental conditions: 

(1) The maintained inside temperature is that normally existing at 
the breathing line (5 ft. above the floor) and about 5 ft. from the wall. 
The breathing line is more often mentioned hereafter as the datum line. 

(2) The basic rate of transmission for any substance is the number of 
B.t.u. which will be transmitted in an hour through each square foot of 
surface of that substance when the outside temperature is zero and the 
maintained inside temperature is 70 deg. fahr. 

(3) From the above it will be evident that the basic rate is that which 
is transmitted at the datum line. 

21 




(DiO'*cocM'-oo)a3r>*co 
S3dnXVy3dlAI31 3aiSNI aSNIVlNIVW QNV 3aiSinO N33M±3a 30N3a3Jdia 

22 



In many structures with a ceiling height of 20 to 30 ft., with no 
mechanical agitation and a low transmission rate through the roof, the aver- 
age increase in temperature recorded above the datum line to a point close 
under ceiling has been fully 1 deg. fahr. per ft. In other buildings of similar 
height with cold roof the average rise has been less than \'2 deg. per ft. 

The downward circulation set up by the absorption of heat from the 
air near cold enclosing surfaces tends to agitate the entire contents and 
reduce the stratification effect. The greater the difference between the 
exterior and the maintained interior temperature, the greater the agitation 
and the less the heat rise per unit of height above the datum line. 

In estimating heat flow, the average height above the datum line for 
each class of service should be considered. Due to the increase in tempera- 
ture above the datum line, the transmission rate for each surface will cor- 
respond to that of the temperature of the strata at the average height above 
datum of such surface rather than that at datum line. 

Where the space above the ceiling is heated, the temperature of the 
strata closest to ceiling will be the highest. In such case it is usual to con- 
sider the average temperature to be that midway between the datum line 
and the upper edge of the vertical enclosing surface and obtain from Figure 




Fig. 3-2. Illustrating heat stratification 
23 



3-1, the percentage to be applied to the basic transmission rate of the 
surface under consideration. 

In the case where the space above the roof or ceihng is cold, the tem- 
perature of the strata ceases to increase beyond a height somewhat below 
such roof or ceiling; the distance depending on the rate of transmission 
through the roof. In this case it is necessary to assume two limits when 
correcting the basic factor of the enclosing surface to allow for stratification. 
It is usual to consider the average temperature in this case as that midway 
between basic level and a level five feet vmder the cold roof. 

The temperature does not always continue to increase in equal amount 
per unit of elevation above the datum line and in very high rooms the level 
at Avhich it ceases to increase is likely to be more than 5 ft. below the cold 
ceiling. 

In rooms with a ceiling height over 10 ft. where air is mechanically 
agitated, there will, in most cases, be a higher average temperature than that 
at the datum line with a consequent increase in transmission rate; this, how- 
ever, will be materially less than in cases of similar height where there is 
no mechanical agitation. 

Heat losses through monitors must be specially considered. In such 
cases it is usual to install heating surfaces within the monitor construction, 
and for that reason the entire monitor construction should be considered 
as an individual unit of enclosure with an imaginary floor across the space 
between the lower edges of its vertical sides. 

However, the factors for stratification for figuring heat losses from 
monitors should disregard the 5-ft. datum line; that is, assuming that the 
temperature at this imaginary floor line is approximately 70 deg. 

In the cases where consideration must be given to the transmission 
of heat through surfaces at a level beneath the datum line it is advisable 
to disregard stratification and estimate the heat transmission at the difference 
between the temperature at the datum line and at the other side of exposed 
surface. 

Basic factors for average height above datum should be fixed on the basic 
temperature difference of zero outside and 70 deg. fahr. maintained inside. 

If the outside temperature for which any particular enclosure is figured 
is different from zero, or if the temperature to be maintained at the breathing 
line is more or less than 70 deg., or if both inside and outside temperatures 
are different from the basic tables, the rates of transmission should be ad- 
justed for the new difference in temperature by factors obtained from Figure 
3-1, and applied to all transmission losses through the structure. 

It is hoped that in the next edition of "Steam Heating," the result of 
tests now under way will be sufficiently complete to indicate the probable 
maximum degree of stratification likely to be encountered in the erecting 
shops and other structures with high ceilings, which are with increasing 
frequency presenting their problems to the Heating Engineer. 

To obtain the maximum transmission rate due to the average height 
above the floor of various surfaces mentioned in tables on following pages, the 
formulae on next page should be employed and a probable maximum value 
given to S. the rate of heat increase due to stratification. 

24 



Windows, doors, walls, and other vertical surfaces 

T, =T + S('^ + D — 5) Formulae 3-1 

Roofs, ceilings, or other liorizontal or sloping surfaces 

Where upper side is cold Where upper side is heated 

T, = T + S(H2- 10) Ti = T + S(H2-5) 

in which 

T = temperature at the datvun hne. 

Ti = average temperature due to stratification at mean height of the 

surface above datum 
S =rate of heat increase above datum, in degrees per foot, due to 

stratification. 
H = height, in feet, of upper level of vertical surface above lower edge. 
H2 = average height in feet above floor of nearly horizontal surface. 
D = height in feet aboA^e floor of lower level of vertical surface. 



Basic Factors: Assuming a value of S in Formulae .3-1, Ti may be 
found for any given condition and bj^ referring this Ti to Figure 3-1, the 
percentage to be applied to the basic rate maj^ be found. If the tempera- 
ture conditions are other than basic (zero deg. to maintained 70 deg.) the 
rates of transmission for heights other than basic should be adjusted to 
the new temperature difference. 

The heat transmission values in the following tables have been proven 
by experience to be approximately correct. These values may need revision 
when results are published, of tests contemplated by the Research Bureau 
of the American Society of Heating and Ventilating Engineers. 

Table 3-1. Walls, Clapboard 

Construction Basic factor, to 70 deg. 

Clapboard on studs, bare 50 

Clapboard on studs, with lath and plaster 35 

Clapboard and paper on studs, with lath and plaster 30 

Clapboard on studs, with 1-in. sheathing, bare 40 

Clapboard on studs, with 1-in. sheathing, papered 35 

Clapboard, with 1-in. sheathing on studs, lath and plaster 25 

Clapboard and paper, with 1-in. sheathing on studs, lath and plaster 20 

Clapboard on studs, with brick fill, bare 28 

Clapboard on studs, with brick fill, papered 25 

Clapboard on studs, with brick fill, lath and plaster 22 

Clapboard and paper on studs, with brick fill, lath and plaster 20 

Clapboard and sheathing on studs, sawdust fill, lath and plaster 15 

Clapboard, paper and sheating on studs, sawdust fill, lath and plaster 10 

Table 3-2. Interior Walls 

Construction Basic factor, to 70 deg . 

Plaster, wood lath, studs, wood lath and plaster 24 

Plaster, metal lath, studs, metal lath and plaster 28 

Studs, wood lath and plaster 42 

Studs, nielal lath and plaster 48 

4-In. hollow tile plastered one side 40 

4- In. hollow tile plastered both sides 35 

2-In. gypsum block plastered one side •. 45 

2-In. gypsum block plastered both sides 42 

25 



Table 3-3. Walls, Stucco on Studs 



Construction 



Basic factor 
to 70° 



Wood 



Plaster Stucco on lath, with wood 

lath and plaster on the inside 10 



1^^ 



Studs 
Metal 



Stucco on metal lath, with 
Plaster nietal lath and plaster on the 

inside 15 

''^tuds 



Table 3-4. Walls, Corrugated Iron 



Construction 



Basic factor 
to 70° 



Cof.^Y -jjjlJs Plain loose construction on 

'™" G' «'f framework 125 

im'n "-0 -leaks Tight construction on frame- 

^"'" 6-' no Air work 90 



Cot- 

Iron 



,^ood On 1-in. tongue-and-groove 

sheathing 45 



Table 3-5. Walls, 


Brick 


Thickness 
in incties T 


Basic factor 
to 70° 


Plain 





< T > 



4 
8 
12 
16 
20 
24 
28 
32 
36 



45 
30 
22 
18 
16 
14 
12 
10 
9 



Plastered inside 



4 
8 
12 
16 
20 
24 
28 
32 
36 



40 
28 
20 
15 
14 
12 
11 
10 



Furred and plastered inside 



< T > 

i| 



4 
8 
12 
16 
20 
24 
28 
32 
36 



30 

20 

15 

12 

11 

9 

8 

7 

6 



Table 3-6. Walls, Hollow Tile Faced with 
Brick 



Thickness 
in inches 



Basic factor 
to 70° 



■^B-> 


a 

D 

n 

D 



Brick 



Tile 



Plain 



4 


25 


8 


20 


12 


14 


16 


10 



■^B >|< T > 








□ v 



Plastered inside 



4 

8 

12 

16 



20 
16 
12 




Furred and plastered inside 



12 
16 



16 

14 

12 

8 



Table 3-7. Walls, Concrete Faced with 
Brick 4-in. Thick 



Tliickness 
in inches 



Basic factor 
to 70° 



■ee-=> <i-C-i> 



Brick 



Concrete 



Plain 



4 


4 


35 


4 


8 


28 


4 


12 


22 


4 


16 


18 



"i-B^ *C* 



Plastered inside 



4 


4 


32 


4 


8 


25 


4 


12 


19 


4 


16 


16 




Furred and plastered inside 



4 

8 

12 

16 



25 
20 
16 
12 



26 



Table 3-8. WaUs, Hollow Tile 



Thickness 
in inches T 



Basic factor 
to 70° 



Plain 



4 

6 

8 

10 

12 



45 
40 
28 
24 
18 



Table 3-9. Walls, Concrete 4-in. Thick 
Faced with Stone 



Thickness 
in inches 



Basic factor 
to 70° 



■tS*<C^ 






Concrete 



Stone 



Plain 



4 

8 

12 

16 



50 
40 
35 

27 





*^^*j<rO 




Plastered inside 






$•:: 


;; 


4 


4 


45 




*:«S 


J 


4 


8 


36 




■■',.■6; 


'.'• 


4 


12 


32 




m 


i 


4 


16 


24 



<S*«€-!> 



i 



Furred and plastered inside 



4 
4 
4 
4 



4 

8 

12 

16 



Table 3-10. Walls, Sandstone or Limestone 



Thickness 
in inches T 



Basic factor 
to 70° 




Plain 



1 

6 
8 
10 
12 
16 
20 
24 



75 
65 
55 
50 
45 
38 
33 
27 




Plastered inside 



4 
6 
8 
10 
12 
16 
20 
24 



67 
58 
49 
45 
41 
34 
29 
24 



Stucco, furred and plastered inside 



4 
6 
8 
10 
12 
16 
20 
24 



50 
43 
37 
33 
30 
2i 
22 
18 



Ta')le 3-11. Walls, Hard Stone or Concrete 



Thickness 
in inches T 



Basic factor 
to 70° 



Plain 



4 
6 
8 
10 
12 
16 
20 
24 



70 
60 
50 
45 
40 
35 
27 
20 




Plastered inside 



4 
6 
8 
10 
12 
16 
20 
24 



63 
54 
45 
41 
36 
32 
24 
18 




Stucco, furred and plastered 



4 
6 
8 
10 
12 
16 
20 
24 



47 
40 
33 
30 
27 
3 
18 
13 



Glass- 



Glass- 



Glass- 
Solid Metal 



Glass-- 



Table 3-12. Windows 



Construction 



Glass 



-!^ 



Glass 



^^ 



Wood sash, 
single glazed 

Wood sash, 
double glazed 

Solid metal sash, 
single glazed 

Hollow metal sash, 
single glazed 

Solid metal sash, 
double glazed 

Hollow metal sash, 
double glazed 



Basic 
factor 
to 70° 



75 



The factors in this table are for trans- 
mission rates at the datum line 5 ft. from 
floor and a temperature of 70 deg. fahr. 
The temperature Ti at the centre of a 
window of any height above the floor will be 



Ti = 70 -)-S 



42 



(^+D-5y 



H = 



D = 



Where S = rate of heat increase above 

datum in degrees per foot, 

due to stratification. 

= the number of feet of height 

of the upper edge of window 

opening above lower edge. 

= the number of feet of height 

of the lower edge of window 

opening above the floor. 

(See Figure 3-2) 

With Ti established, the factor for cor- 
recting the tabular values wiU be deter- 
mined from Fig. 3-1. Apply this corrected 
factor to the entire area of window opening. 
Monitors must be considered as separate problems, as if they are structures of themselves with 
theoretical floors at the level of the base of the monitor. Their transmission losses and the sizing and placing 
of radiating surfaces should be figured accordingly. The factor should disregard the usual 5-ft. datum 
line. That is, assume that the temperature at this imaginary floor line is 70 deg. fahr. 

Table 3-13. Doors and Wood Partitions 



90 



80 



65 



45 



Construction 



Basic factor, to 70 ° 



^-In. to 1-in. thick, tongued-and-grooved 45 

1 -In. to 1,14 -in. thick, tongued-and-grooved 40 

lJ4-In. to IJ/^-in. thick, tongued-and-grooved 35 

1 J^2-In. to 2-in. thick, tongued-and-grooved 30 

2 -In. to 2V2-in. thick, tongued-and-grooved 25 

21-2-ln. to 3-in thick, tongued-and-grooved 20 

Table 3-14. Roof Construction 

Construction Basic factor, to 70** 

Flat tile on strips 75 

Flat tile on sheathing 45 

Slate on strips ■ • 78 

Slate on sheathing and paper 35 

Corrugated iron on strips 125 

Corrugated iron on sheathing 45 

Tin on strips 110 

Tin on sheathing 40 

Tin on sheathing with paper 30 

Shingles on strips 60 

Shingles on sheathing 30 

Shingles on strips over tar paper and sheathing 15 

Reinforced concrete composition 2-in.. paper, tar and gravel 50 

Reinforced concrete composition 3-in., paper, tar and gravel 45 

Reinforced concrete composition 4-in.. paper, tar and gravel 40 

Hollow tile 4-in.. paper, tar and gravel 20 

HoUow tile 6-in., paper, tar and gravel 18 

Metropolitan 3-in., paper, tar and gravel 20 

MetropoUtan 4-in., paper, tar and gravel 15 

1-In. wood with 5 to 8-ply paper, tar and gravel 20 

1-In. wood with felt roofing 25 

1 J^-ln. wood with 5 to 8-ply paper, tar and gravel 18 

2-ln. wood with 5 to 8-ply paper, tar and gravel 15 

23/^-In. wood with 5 to 8-ply paper, tar and gravel 12 

2-ln. Federal cement tile, paper and tar and gravel 50 



28 



Table 3-15. Roof Glass and Skylights 
The surface to be considered is the total surface of glass and frame 



Construction 



Basic factor, to 70° 



Wood 



Glass- 
Wood 



Glass -^ 
Solid M elal 

Glass -^ 
Hollow Melal 



Glass'' 
Solid Metal 



Wood sash, single glazed. 



^ Gl ass 
1^ r'^ Wood sash, double glazed . 



-|^;-J'.',' \ Solid metal sash, single glazed . 



_ |r ( Hollow metal sash, single glazed . 



'Glass — _^ Solid metal sash, double glazed . 



Glass--^ 
^^i^Meial ^"^'p S— , Hollow metal sash, double glazed . 

Glass -^ 



75 
42 
90 
80 
65 
45 



Table 3-16. Floors Above Cold Space 

The factors are for to 70 deg. difference in temperatures. For any other difference, the basic factor 
should be corrected in accordance with chart, Fig. 3-1 



Above cold space 



Description 



Basic factor, to 70° 





^ Lath jnd Plasier- 
Wood— ^ 



m 



U-"Hoisl Wood -^ JoisI iid 

^ - Lath and Plaster "^ 
Wood -^ 



E 



[ihoisi 



Joistl^ 



'-Insulation ^-- Lath and Plaster 

Wood -A Wood-^ 



Concrete 
Wood ^, 



Concrete-"' 



Mill construction, .S-in. wood and paper plus Js-in. surface . 12 

1-In. single wood floor on joists 25 

2-In. double wood floor on joists 15 

l-In. single wood floor on joists with lath and plaster 1-1 

2-In. double wood floor on joists with lath and plaster 10 

2-In. double wood floor on joists with insulation and lath and 

plaster 4 

2-In. double wood floor on 4-in fireproof concrete 6 

1-In. wood flooring on double wood and 4-in. fireproof con- 



crete . 



Reinforced Concrete^" 



^^^!^ 



n 



,:^^.^^ 



Reinforced Concrete' 
Reinforced Concrete-'' 
Reinforced Concrete-'^ 



4-ln. concrete slab, metal reinforced 70 

6-In. concrete slab, metal reinforced 60 

8-In. concrete slab, metal reinforced 50 

10-In. concrete slab, metal reinforced 40 



29 



Table 3-17. Floors Laid on Ground 

These factors are for to 70 deg. difference in temperature. It is usual, however, to assume the 
temperature of the ground beneath the floor as 50 deg. fahr. For this difference the above basic factor 
must be corrected by means of the chart in Fig. 3-1 

Basic factor 
to 70° 



Construction 



^Sleepers^ Ground' 

Wood-^, Walcrprooling , 



1 



Concrete-^ 



f^ 73" 



2 'Wood blLLptr 



^ Concrete 



Ground^ 

Conrrete- ^ 



VCinc 



Cinder till 



Ground'^ 



1-In. single wood floor on wood sleep-irs 9 



2-In. wood floor on 4-in. water-proofed concrete 7 



3-In. double wood floor with paper between on sleepers in 
4-in. concrete 4 



4-In. concrete floor on ground 22 



4-In. concrete floor on cinder fiU 20 



I 



.^//////////////•'^ 

Concrete 



Ground' 



rf 



Crick^^ 

.1.1 II II I I. I J 11 .Z3I 



'y777777P7i^7777777777. 



1-In. tile floor on 4-in. concrete. 



2}^-In. brick floor on 4-in. concrete . 



20 



Table 3-18. Ceilings 

The factors are for to 70 deg. difference in temperatures. For any other difference, the basic factor 
should be corrected in accordance with chart. Fig. 3-1 



Construction 



Basic factor 
to 70° 




Plaster ' 



Wood-^ 




'Wood Lath Plaster^ 



BE 



-Joists - 



3sr 



Metal Ceiling 



Wood lath and plaster on joists 42 

Metal lath and plaster on joists 46 

1-In. single wood floor on joists with wood lath and plaster ... 18 

2-In. double floor on joists with wood lath and plaster 14 

1-In. single wood floor on joists with stamped metal ceiling . . 25 
30 



CHAPTER IV 

Air Infiltration 

WIND blowing against walls causes a leakage of air into the enclosure 
and an outward leakage from the enclosure through the opposite 
sides. Additional leakage is caused by temperature difference within 
and without regardless of wind velocity. These leakages are sometimes 
referred to as air change, but in this book are called air infiltration. 

As the air enters and leaves the enclosure at different temperatures, 
sufficient B.t.u. or heat units must be provided to heat this air between the 
two temperatures. Air infiltration therefore becomes one of the important 
factors in the determination of the heat requirements of a room or an en- 
closure. 

Some rules for heat requirements of an enclosure regard that portion 
due to ah" infiltration as an additional quantity to be based upon an arbi- 
trary hourly air change or upon a certain percentage of the best trans- 
mission factor. 

Examination of the air infiltration shows that most of the air leaks are 
around the doors, windows and other similar openings. The quantity that 
expresses the heat requirements due to this infiltration of cold air should 
therefore be based upon the sum of the openings through which this leakage 
occurs, rather than upon the area of the doors, windows and similar openings 
of the structure. 

Any determination of the quantity of air infiltrated must take into 
consideration the velocity and direction of the wind in relation to the 
openings of the enclosure. Where an enclosure has openings on more than 
one side, the infiltration for all openings must be determined and the 
radiation for this loss proportioned and located according to the maximum 
degree of infiltration that may occur on any side. This method will give an 
excess of radiation on the sides where leakage is outward, but there is no alter- 
nate without having some sides of the room feel cool at some wind direction. 

In small rooms having window exposures on more than one side, and 
which ordinarily can be heated with one radiator, it is only necessary to 
consider the infiltration for the side of maximum exposure and locate the 
radiation on that side. 

The leakage in narrow monitors and rooms where cold drafts will not 
be objectionable may be considered only on the side where maximum wind 
velocities occur. A portion of the heat to care for this infiltration can then 
be applied to the other side. Where the wind strikes the surface at an angle, 
the resultant velocity at right angles to the surface must be considered. 
This is equal to the actual velocity times the sine of the angle of incidence. 

Normally the same maximum wind velocity should be considered on 
the north and west sides, while on the south and east sides one-half of these 
velocities may be used except where special wind conditions exist. 



A suggested extreme condition for New York and vicinity would be 
15 miles per hr. wind velocity with a temperature of zero. Generally low 
wind velocities prevail at extremely low temperatures. 

The many variables make reference to experiment more reliable than 
attempts to determine theoretically the perimeter air infiltration of windows, 
doors and similar openings. Little dependable experimental data is avail- 
able at present, but such as is now obtainable must be used as a basis 
until better is to be had. 

Experiments on air infiltration of windows have been made by using a 
fan to direct wind velocities against a test window set in the side of a tight 
enclosure and having an opening for pitot tube readings on the opposite 
side. Further details regarding some of these experiments by Whitten will 
be found in the 1908 Transactions of the American Society of Heating and 
Ventilating Engineers, and others by Voorhees and Meyer in the 1916 
Transactions. 

Similar tests are being conducted by the Research Bureau of the 
American Society of Heating and Ventilating Engineers and the United 
States Bureau of Mines. In these tests natural air velocities are used and 
the infiltration determined by reduction in carbon-dioxide content of air 
in the room. A preliminary report of these tests describing the method in 
detail was given by Mr. O. W. Armspach in the Journal of American Society 
Heating and Ventilating Engineers, Januarj^ 1921. 

Figure 4-1 gives the approximate leakage in cubic feet per minute per 
lineal foot of sash perimeter for double-hung locked windows, with and 
without metal weather strips. 

The type and construction of the windows to be used shoidd be definitely 



bu / ■T/ ■ 1/ ■■■■,■ ii-'T 1 ;r ■-■■ 1 1 








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2 ;i 4 5 C 7 8 

AIR INFILTRATION IN CUBIC FEET PER MINUTE PER LINEAL FOOT OF APERTURE 

Fig. 4-1. Air infiltration for double-hung windows 
32 



10 



known before the infiltration is estimated and this data recorded in a similar 
manner to data regarding the type of wall, roof or other construction of the 
enclosure. 

Due allowance should be made for special sash. The meeting rail 
must be considered in measuring the perimeter of double-hung sash. 

In windows with steel-section frames properly bedded, only the perim- 
eter of that portion which opens, or the ventilating sash, need be considered. 

In industrial plants where it is intended to install mechanical exhaust 
systems for removing dust or fume-laden air, special means must be provided 
to care for the corresponding increase in infiltration as described on page 65 
of Chapter 7. 

For well-fitting doors the average window values can be used, but 
for sliding and similar poorly fitting doors, as used in industrial buildings, 
the values for a poor window should be used. 

The leakage values as read from Figure 4-1 when multiplied by 60 x 
0.0864 (density of air at zero) x 0.2375 (sp. ht. of air), will give the heat 
units per hour required to warm the infiltrated air from 1 ft. of perimeter, 
1 deg. fahr. 

Exavvple: Assume an average double-hung window 3 ft. wide by 
6 ft. high with a perimeter of 21 ft., outside temperature zero, inside tempera- 
ture 70 deg. fahr. with wind velocity of 15 miles per hr. Referring to 
Figure 4-1, the leakage per foot of perimeter is found to be 1.60. Then 21x 
1.60x60x0.0864x0.2375x70 = 2893 B.t.u. per hr. required to heat the air 
infiltration from this window. 

The following tables will be found useful in determining the heat 
units required to care for the infiltration. These values are for plain double- 
hung windows. If equipped with a good metal weather strip, use 20 
per cent of the tabulated values. 





Table 4-1. 


B.t.u. per Hour Required 


per Lineal Foot of Perimeter for 


Windows 






Infiltration 
















Cu. ft. per min. 














Wind vel. 


per ft. of 




Temperature difference inside and outside of enclosure 




Miles per hr. 


perimeter 


50° 


60° 


65° 


70° 


80° 




5. 


.36 


■->■-> 


27 


29 


31 


35 


•"== 


7.5 


.54 


32 


39 


42 


45 


52 


s? 


10. 


.72 


44 


53 


58 


62 


71 


O.G 


15. 


1.08 


66 


80 


86 


93 


106 




20. 


1.42 


87 


105 


114 


122 


140 




5. 


.56 


34 


41 


45 


48 


55 


»S 


7.5 


.85 


52 


63 . 


68 


73 


84 


%i 


10. 


1.12 


69 


83 


90 


97 


110 


5-? 


15. 


1.68 


103 


124 


134 


145 


165 




20. 


o oo 


137 


164 


178 


191 


219 




5. 


1.07 


66 


79 


86 


92 


105 . 


-! 


7.5 


1.60 


95 


115 


125 


134 


154 




10. 


2.12 


131 


157 


170 


183 


209 


15. 


3.12 


192 


230 


250 


269 


307 




20. 


4.07 


251 


301 


326 


351 


401 



83 



CHAPTER V 

Method of Calculating Heat Requirements 

CHAPTERS 1 and 2 give the general data that must be known in 
calculating the heat requirements of any structure. Several rules and 
formulae have been devised to determine the amount of heat that 
must be supplied to maintain a room or enclosure at a predetermined 
temperature with a known surrounding temperature. Many of these 
formulae were derived when construction, size of window opening, etc., were 
similar and are not flexible enough to cover the problems of today. 

If the air within an enclosure is maintained at a temperature higher 
than that surrounding, there must be a natural transfer of heat through 
the enclosing structure to the air of lower temperatures. This transfer may 
be to the air outside, to any adjoining rooms and to air above and below, if 
these are at lower temperature than that in the room. 

To heat the enclosure to and maintain it at a predetermined temper- 
ature, an equal amount of heat must be supplied at the rate at which it is 
transferred. The most accurate method of determining the quantity 
transferred is to determine the hourly rate of heat transfer from the heated 
enclosure to the surrounding air. This quantity is usually calculated in 
British thermal units per hour; that is, on the B.t.u. basis. 

The total quantity transferred is made up of four principal heat 
requirements. 

The first is the heat required to warm to the desired inside temperature, 
the air that leaks in through the various openings around the window and door 
perimeters, etc., from the outside. To calculate the heat units for these 
requirements, the width and lineal feet of the openings, and the wind velocity 
against the side of the enclosure where the openings are located, must be 
found, and with these data the air infiltration determined. The product of 
the air infiltrated in cubic feet per hour, the density of the air, its specific 
heat and the difference between the inside and outside temperatures will 
give the heat required per hour for infiltration. This subject is further 
discussed in Chapter 4. 

The second is the heat transmitted through the various materials of 
which the enclosure is constructed. To calculate this recjuirement, the area, 
thickness and kind of the various materials through which this transfer 
occurs, and the temperature difference between the air on the two sides of 
the material must be known. 

The product of the area of any material in square feet, the transmission 
coefficient for that material in B.t.u. per hour, and the difference between 
the inside and outside temperatures will give the heat transmitted per hour 
through that material. The sum of quantities so found for all materials 
of the structure is the total loss of heat from the enclosure by transmission. 

A desired maintained interior temperature of 70 deg. fahr. and a mini- 
mum external temperature of zero have been adopted in this book as a 

34 



standard. All transmission coefficients, therefore, are given in B.t.u. per 
hour per square foot of surface for this temperature difference, with correc- 
tion factors for other differences. 

A table of these factors for various materials used in building con- 
struction will be found on pages 25 to 30. 

A third requirement enters into the calculation where the heating is 
not continuous. This may be referred to as a heating requirement, or the 
heat necessary, to raise the air of the enclosure from its initial temperature 
to the desired maintained temperature. It is evident that if only sufficient 
heat is supplied to compensate for the air infiltration and transmission 
requirements, the temperature of the enclosure would approach but not 
reach the predetermined temperature, unless additional heat units are 
supplied for heating an aniount of air equivalent to the cubic contents of the 
space to be heated. To calculate this requirement, cubic contents of the 
enclosure, initial and final temperatures of the internal air, and time desired 
to raise the air through this temperature range must be determined. 

The product of the quantity of air in cubic feet, the density of the air, its 
specific heat, and the temperature difference, is the quantity of heat required 
for initial heating of the air. If this quantity be then multiplied by the 
reciprocal of the heating-up period in hours, the product will be the quantity 
of heat that must be supplied per hour during the heating-up period, to 
supply the heat absorbed in heating the air. 

A fourth heat requirement should be included in calculations where 
the heating is not continuous, and where large quantities of materials 
such as metal, water, glass, etc., are stored in the enclosure and must be 
heated like the air contents, from initial to maintained inside temperature. 

The product of the weight of such material in pounds, its specific heat 
and the desired temperature range is the heat absorbed by the material. 

This quantity must also be multiplied by the reciprocal of the heating- 
up period in hours to obtain the hourly heat requirement during initial 
heating to compensate for this absorption of heat. The longer the heating- 
up period selected the less will be the difference in the hourly requirements 
during initial and maintained heating. 

Where large quantities of such stored materials are taken into and re- 
moved from the enclosure at intervals the heat absorbed by these materials 
must be considered. 

The sum of these four requirements gives the total hourly rate at which 
heat must be supplied to maintain the enclosure at a predetermined tem- 
perature, or to raise the temperature of the enclosure from its initial to 
predetermined temperature, as the case may be. 

Applying this method of calculating heat loss requirements. Figure 5-1 
represents the main floor of a residence with warm basement and second 
floor. Under these conditions, no ceiling or floor loss need be considered. 

The quantities taken from the plan and the basic data are entered on 
the Heat-requirement Computation Sheet, Table 5-1. 

The requirements are figured for each exposed side as in Room 1. 
The requirement for the north side is 12230 B.t.u., for the east side 4830 
B.t.u., for the west side 1635 B.t.u. and the B.t.u. required for initial heating 

35 



I WINDOW RADIATOR 

17 SEC. 
I 20'= 85 SQ.FT. 



/ J COL. T8 sec. 

'' 28'= 72 so. FT 
ENCLOSED 
BOTTOM CBlLLE 9" WlOE X ^ 

LENGTH OF RADIATOR FREE 

TOP GRILLE WIDTH X f- OF GRILLE +4 

LENGTH OF RADIATOR P£R CENT 



fr~B 



REGISTER 312 SO. 



Ui ? RADIATORS EACH 

f 1 COL. G EEC, 3E=1B SQ.FT. 



ROOM No. 1 



ir-JJ 



= ^. 



"*-« 



ROOM No. 2 



ROOM No. 4 



2 COL. 14 SEC. 
"-^^1 SQ.FT. 



HEATED 
ROOM 



Cz 



[U 



J RADIATORS EACH — — ^ 
1 COL. 5 SEC. 32 =13i!; 5Q.FT;~ 



ROOM No. 3 



3 RADIATORS EACH 
2 COL. 30 SEC. 23' = 46 f SQ.FT. 



ROOM 
NO. 5 



1 COL ■; EEC \^ 
32"=12- SQ.FT. 



n sec. 30" VENJO 
ON 4" CENTERS !i._ 
8i 5Q.FT. 




I I 3 SEC. 50 ' VENTO "DAMPEH't?J_j 

:,-' "-I /ON 1" CENTERS /f*"""^ 

ir"^., JC SQ.FT. T6S0lN^' Ir"--? 



5 SEC 30 VEMTO 
ON 4" CENTERS 
j.--^40 SO FT. 




REGISTER |.;3 SO.IN. 



BUILDING A 



Fig. 5-1. Plan of residence floor used as basis for heat-requirement computation sheet, Table 5-1 



of the air contents is. 632, ■ making a total maximum requirement of 19,327 
B.t.u. per hour. The heat supply for this room should he placed under 
the north window. 

The requirements in B.t.u. per hour as taken from the computation and 
divided in a similar manner are marked on the plan for each room. 

Another illustration of the method of calculation is given in the Heat- 
requirement Computation Sheets, Table 5-2, for the factory building shown 
in Figure 5-2. 

The calculation has been separately made for the sections as marked 
in the figure, so that the losses may be proportioned to the exposures. 

It will be noted that the correction factors are used to change the 
70-deg. temperature-difference coefficients to correct values for the given 
temperature differences which may vary due to stratification. 

In section C, the calculations for the north and south walls with their 
windows and doors from the floor to line a — b were made separately from 
the balance of the losses for this section. 

As the air infiltration from the upper sash would not be felt directly by 
the operators in the building, the infiltration has been calculated for only 
the west or side of maximum wind velocity. 

The infiltration factor for the doors has been taken as that of a poor 
window, and in calculating the window infiltration losses only the perimeter 
of the ventilating portion of the window has been considered. 

The requirements for the various walls and sections as taken from the 
calculations are marked on the drawing in their relative locations. 

36 




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CHAPTER VI 

Method of Computing and Selecting 
Heating Surface 

DETERMINATION of the heating surface depends first upon the 
total hourly heat requirements which are assumed to have been 
calculated as described in the preceding chapter. The heating 
surface must supply heat units to equal the requirements and should be 
of the form that best fits the conditions for the room or enclosure. 

The method of heat supply must first be determined — that is, whether 
the heating surface is to be direct, indirect or direct-indirect. The last two 
methods are used principally where ventilation must be considered in addition 
to the heating reciuirements. although the indirect method is considerably 
used where it is not desired to have the surface located in the room to be heated. 

Normally, the heat should be supplied at the locations where the greatest 
requirements occur, and this is generally at the windows, where, in addition 
to a high transmission requirement, there is the air infiltration requirement 
as well. 

Rooms or enclosures where more than one unit of radiation is to be 
installed should have the heating surface divided in proportion to the 
requirements of the spaces served. 

Heating surface placed under the windows should not project above the 
sills, should be as wide as the window openings, and should also be installed 
with a 2J^-inch space between the wall and the surface, as this distance gives 
maximum efficiency of heat emission. 

Direct heating surface, inasmuch as it is used in a large majority of 
installations, should be considered first. Residences, office, school, library, 
hospital and similar buildings usually have cast-iron column radiation 





y>i.Uii|-i'^f^iy; ^^ 




Fig. 6-1. Cast-iron wall radiation on side walls under windows, for heating a factory building 

42 




Fig. 6-2. Connections to a direct hot-water type radiator showing modulation supply valve and 

thermostatically actuated return trap 

together with some cast-iron wall radiation. Factory and manufacturing 
buildings are usually heated by means of wrought-iron or steel pipe coils or 
cast-iron wall radiation. 

Hot-water pattern radiation is preferable for those systems in which 
modulation supply valves are to be used. The supply valve should be placed 
at the upper inlet and the return trap at the lower opening diagonally 
opposite. 

Good practice in the use of groups of wall radiation suggests that no 
individual group exceed .30 ft. in length, as expansion and contraction 
become an important factor on longer groups. Where greater lengths of this 
type of radiation must be used, the supply connection should be made at 
top and bottom and expansion and contraction properly provided for. 

Pipe coil practice demands a spring or mitre piece in the coil to provide 
for expansion and contraction, and the desirable length is limited to 60 ft. 
not including the mitre piece. Coils should be securely anchored at the 
return header so as to throw the expansion toward the mitre end, the length 
of which should be not less than one-twelfth the coil length for 1-in. pipe 
and one-tenth for 13^-in. or 13>2-in. pipe. 

43 




Fig. 6-3. Arrangement of cast-iron wall radiation on side wall of a factory building 













































+ 50 


















































































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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

Length of Radiator in Sections 
Fig. 6-4. Percentage of variation in heat emitted from cast-iron heating surface per square foot for 
various numbers of sections as compared with a standard 10-section radiator 

44 



The amount of heat emitted from any given type of direct heating 
surface is usually stated in B.t.u. per hour per square foot of heating surface. 
This heat is given off in two ways, by convection directly to the air which 
passes over the heated surface, and by radiation directly to surrounding 
materials independent of that carried off by the air. The heat given off by 
radiation does not heat the air through which it passes, but travels in straight 
lines and heats the objects upon which it impinges. 

After selecting the type of surface best suited for the particular case, 
the number of square feet of heating surface required should be deter- 
mined next. The total number of heat units that must be supplied per hour 
divided by the heat units emitted per hour per square foot of heating surface 
gives the required surface in square feet. 

Table 6-1 will be of assistance in determining the heat emitted by dif- 
ferent types of surface. 

Table 6-1. B.t.u. Emitted per Hour per Square Foot of Heating Surface* 

Radiators 10 Sections Long 
Steam Temperature, 215 deg. fahr. Room Temperature, 70 deg. fahr. 













Percent 


Number 


Height 


B.t.u. 


B.t.u. 


Total 


convected 


of 


of 


by 


by 




heat of 


columns 


radiator 


convection 


radiation 


B.t.u. 


total heat 


One 


38 in. 


150 


106 


256 


58.6 


" 


32 in. 


158 


108 


266 


59.4 


*' 


26 in. 


162 


111 


273 


59.4 


" 


23 in. 


160 


119 


279 


57.4 


** 


20 in. 


166 


117 


283 


58.7 


Two 


45 in. 


148 


86 


234 


63. 


'* 


38 in. 


148 


92 


240 


62. 


'* 


32 in. 


154 


94 


248 


62. 


*' 


26 in. 


149 


106 


255 


58. 


<« 


23 in. 


151 


109 


260 


58. 


** 


20 in. 


153 


112 


265 


58. 


Three 


45 in. 


142 


76 


218 


65. 


" 


38 in. 


147 


79 


226 


65. 


*' 


32 in. 


158 


75 


233 


68. 


" 


26 in. 


166 


75 


241 


69. 


*' 


22 in. 


166 


82 


248 


67. 


*' 


18 in. 


162 


92 


254 


64. 


Four 


45 in. 


149 


56 


205 


73. 


" 


38 in. 


150 


60 


210 


71.5 


** 


32 in. 


151 


66 


217 


69.5 


" 


26 in. 


155 


70 


225 


69. 


'* 


22 in. 


156 


76 


232 


67. 


** 


18 in. 


151 


87 


238 


63.5 


Wall radiation 


3 in. wide 


14 in. 


152 


171 ' 


323 


47. 


(C it 


22 in. 


154 


156 


310 


49.7 


" 


29 in. 


138 


157 


295 


48. 


Pipe coil 


6-1 li in. pipes 
8-14 in. " 
10-14 in. " 
12-14 in. " 






360 
343 
330 
319 





* John R. AUen, A. S. H. &■ V. E. Journa/— January, 1920 

From Table 6-1 it will be noted that low, narrow surface is most efficient 
and that the efficiency decreases as the height and width increase. 

45 



Some other factors and their effect upon the efficiency of the radiating 
surface are worthy of explanation. 

The preceding table is based upon a radiator 10 sections long. As the 
number of sections decreases, the efficiency increases, due to increase of the 
more efficient end-section surface in proportion to total heating surface; 
also a short radiator emits proportionally more radiant heat than a longer 
one. Figure 6-4 shows the effect of varying the number of sections, and 
that increasing the number of sections above 10 has not as much effect as 
decreasing the number below 10. It will also be noted that a 4-section 
radiator will give off about 10 per cent more heat per square foot of surface 
than one 10 sections long. 



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-40 



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-10 +10 +20 +30 +40 

Percentage Variation in Heat Emission 



+ 50 



+ 00 



+80 



Fig. 6-5. Percentage variation in heat emitted from heating surface due to varying the steam 
temperature from 215 deg. fahr., room temperature 70 deg. fahr. 

46 



Where 215 deg. fahr. is considered as the standard temperature of 
steam in the heating surface, the effect upon the heat emission of tlie 
surface due to varying this temperature is shown in Figure 6-5. The 
percentage variation can be read directly from the curve. 

Example: If steam at a temperature of 230 deg. fahr. is supplied to 
the radiator, the heat emission will be increased 12 per cent over one 
supplied with steam at 215 deg. fahr. 



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Fig. 6-6. 



60 70 80 90 

Room or Surrounding Temperature -Deg. Fahr. 



100 



110 



Percentage variation in heat emitted from heating surface due to 
\ arying the room temperature from 70 deg. fahr. 



The surrounding or room temperature is taken at 70 deg. fahr. as a 
standard. The effect upon the heat emitted from heating surface, due to 
varying this temperature, is shown graphically in Figure 6-6. From the 
curve it will be observed that, for instance, a radiator in a room temperature 
of 60 deg. fahr. will emit 6 per cent more heat than the same radiator in a 
room temperature of 70 deg. fahr. 

The effect on heat emission due to variation in steam temperature is 
much greater than an equal temperature variation in the surrounding or 
room temperature. 

The following example will illustrate the use of the curves in Figures 
6-4, 6-5 and 6-6 for determining the heat emission under given conditions; 
it is desired to know the B.t.u. emitted per hour per square foot of heating 
surface of a standard cast-iron radiator, two columns wide, 38 in. high, 
and six sections long when supplied with steam at 240 deg. fahr. and located 
in a room heated to 80 deg. fahr. 

Referring to Table 6-1, a similar radiator except that it is 10 sections 
long, gives off 240 B.t.u. per hr. per sq. ft., with steam at 215 deg. fahr. 
in room temperature 70 deg. fahr. A radiator six sections long is 4.5 per 
cent, more efficient (Figure 6-4), when supplied with steam at 240 deg. 



47 



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Length of all outlets = length of radiator 

Length of all inlets I = length of radiator 

Width of all outlets O = width of radiator or as 
given in table 

Screens or grilles have 44 per cent free area 



Fig. 6-13 



Enclosures for radiators 
48 



fahr., the efficiency is increased 20 per cent (Figure 6-5), and if located in a 
room heated to 80 deg. fahr. there is a decrease in efficiency of 6 per cent 
(Figure 6-6). The heat emission of the radiator required would be 240 x 
1.045 X 1.20 X 0.94 = 283 B.t.u. per hr. per sq. ft. of radiating surface. 

Painting a radiator influences only the heat emitted by radiation, the con- 
vection factor remaining practically unchanged. As paint affects the surface 
only, the number of coats makes little difference. It seems to depend on the 
last coat applied and when made of flake metal the result is more marked. 

Direct radiators are sometimes set behind grilles or screens, in window 
enclosures or wall recesses, all of which greatly decrease the efficiency of 
the radiation. 

Tests by Professor Brabbee, as reported by George Stumpf, Heating 
and Ventilating Magazine, May, 1914, show that a radiator in an enclosure 
is most efficient when located with 23/^ inches between the wall and radiator 
and between the inside of the enclosure and the radiator. Abstracts from 
these tests follow. 

The inlet and outlet openings of any form of enclosure should extend at 
least the entire length of the radiator. The width of the outlet is usually 
made that of the radiator. Tests show little gain in efficiency for wider 
outlets, but a decrease of about 5 per cent for each inch narrower than 
that of the radiator. 

The outlets and inlets in Tables 6-7 to 6-13 are the full length of the 
radiators. The width of outlet is the width of the radiator except in Table 
6-4, where it is as given. The width of inlet I is as stated in the tables. 




Fig. 6-14. An enclosed radiator having grilles or screens on front and top of enclosure. The 
modulation supply valve control is shown on top of enclosure 

49 



Both openings are covered with screen of 44 per cent free area. 

The design of the screen or grille has no effect provided the free area 
is not changed. 

Figure 6-7 shows a form of enclosure frequently used. 

Table 6-2. Decrease in Radiator Efficiency with Form of Enclosure Shown in Fig. 6-7 

Radiator width Radiator height Width of 1 Decrease in efficiency 

Two-column 42 in. and over 9 in. 15% 

Under 42 in. 9 in. 20% 

Under 42 in. 5 in. 25% 

Three-column 42 in. and over 9 in. 15% 

32 in. to .38 in. 9 in. 15% 

32 in. to 38 in. 7 in. 20% 

26 in. and under 9 in. 20% 

" " 26 in. and under 5 in. 25% 

If the width of inlet is made equal to the free area and not screened, the 
efficiency reduction will remain as above. 

Another form of enclosure, Figure 6-8, gives the effect upon the radi- 
ation efficiency as shown in Table 6-3. 

Table 6-3. Decrease in Radiator Efficiency with Form of Enclosure Shown in Fig. 6-8 

Radiator width Radiator height Width of O Width of I Decrease in efficiency 

Two-column 42 in. and over 8 in. 8 in. 20% 

32 in. to 38 in. 9 in. 9 in. 20% 

32 in. to 38 in. 7 in. 7 in. 25% 

'' " 26 in. and under .6 in. 6 in. 33% 

Three-column 26 in. and over 9 in. 9 in. 20% 

" " 26 in. and over 6 in. 6 in. 25% 

Enclosure of the form shown in Figure 6-9 is sometimes used and by 
test gives the following effect: 

Table 6-4. Decrease in Radiator Efficiency with Form of Enclosure Shown in Fig. 6-9 

Perforated screen fuU front of enclosure only — decrease in efficiency 20% 

Same screen with deflector — " " " 15% 

If an outlet is provided in addition to front screen and made equal to 
width and length of the radiator, the efficiency decreases only 10 per cent. 

Sometimes it is desirable to set the radiators in wall recesses, as shown 
in Figures 6-iO and 6-13 which causes a decrease in efficiency as follows: 

Table 6-5. Decrease in Radiator Efficiency Due to Wall Recess Fig. 6-10 

When = 13^ inches — decrease in efficiency 11% 

" = 3 :%) " " " 7.3% 

"0 = 4 "J " " " 6% 

The distance a has little or no effect, and therefore need only be 
sufficient for connections to the radiator. 

A shield in front of a radiator as shown in Figure 6-11 increases the 
radiator efficiency as follows: 

50 




Fig. 6-15. An enclosed radiator in a window seat, with grilles of rattan cane. The modulation 
supply valve control is placed on the window seat 

Table 6-6. Increase in Radiator Efficiency by Use of a Shield Fig. 6-11 

Height of shield, H 52 in. 

Width of open slot, 1 6J4 in. 

Increase in efficiency 2. 2% 

Another form of enclosure, shown in Figure 6-12, by test gives the fol- 
lowing effect upon the radiator efficiency: 



52 in. 


52 in. 


72 in 


9 in. 


12 in. 


12 in 


6.3% 


12.5% 


13% 



Table 6-7. Decrease in Radiator Efficiency with Form of Enclosure Shown in Fig. 6-12 



Width I 
Decrease 


in efficiency . 




. Sin. 

.10% 


6 in 

15% 


5 in. 

20% 


4 in. 3 in. 

25% . 33% 


Table 6-8. 


Comparative B.t 
Based 


u. Transmission 
on 3-coluinn 30-in. 


and Cost of Cast-Ii 
radiation as 1.00 


on Heating Surface 



Rad. 


Relative 


cost of r 


adiator per sq. ft. 


B.t.u. given 


off per s 


,. ft. 


Relat 


ve cost based on heating 
efficiency 


height 


1 


2 


3 


4 


1 


2 


3 


4 


1 


2 


3 


4 




Column 


Columns 


Columns 


Columns 

1.43 


Col. 


Col's 


Cors 


Col's 


Column 


Columns 


Columns 


Columns 


18" 






1.43 






2,54 


238 






1.27 


1.36 


20" 


1.49 


1.43 






283 


265 






1.19 


1 0'7 






22" 






1.28 


1.28 






248 


232 






1.17 


1 25 


23" 


1 38 


1.31 






279 


260 






1.10 


1.14 






26" 


1.30 


1.25 


1.18 


1.18 


273 


255 


241 


225 


1.08 


1.11 


1.10 


1.18 


32" 


1.18 


1.13 


1.08 


1.08 


266 


248 


233 


217 


1.01 


1.03 


1 . 04 


1.12 


38" 


1.09 


1.04 


1.00 


1.00 


256 


240 


226 


210 


.96 


.9^ 


1.00 


1.08 


45" 




1.04 


1.00 


1.00 




234 


218 


20,3 




1.01 


1.04 


1.11 



These tables are based on investigations of 10-section radiators 

For Radiators under 6-section, the B.t.u. per sq. ft. increases rapidly and the tables cannot be used 
with accuracy. Above 6-section the error is small 

.51 



Table 6-8 will be of interest as it compares the relative costs of cast- 
iron heating surface of different heights and number of columns where the 
efficiency of the surface is taken into consideration. 

As an example, compare the relative cost of 3-column 38-in. with 
single-column 23-in. surface. The 3-column surface cost is figured as 1.00 
and it emits 226 B.t.u. per sq. ft. per hr. The single-column radiator 
cost is 1.36 but it emits 279 B.t.u. per sq. ft. per hr. Although the actual 
cost per square foot for the single-column radiator is 36 per cent more than 
for the 3-column, the 1-column radiator is 23 per cent more efficient in 
heat emission. If this increase in heating efficiency is considered, the cost 
of the single-column radiation is only 10 per cent more. 

Indirect heating surface generally refers to that located below and 
outside of the room to be heated. (See Figure 6-16<) The heat is delivered to 
the room by a system of ducts that convey^fWh'air from outside. The air 
passes over the surface, is heated and then discharged into the room through 
^register faces located in the room floor or wall. This method of heating is 




Ceiling Line 



1^" Air Line into Top of 
Dry Return. ?^"when Dry 
Return is over 10' 0" 
Distant 



Dry Return 



Supply Main 



Indirect Radiator 
Parts of Casing removed 

12"x 12" Sliding Door at 
Bottom of Casing 



Full size Nipple to outside of Radiator , 
Casing, than a full size Ell and Nipple 
connecting to a reducing Ell Not less tfian 30" 

Union above Water Line of Boiler- 
Water Line of Boiler ^^ 



Connect into Wet Return Main- 



Fresh Air 



Quadrant Damper 
' Clean Out Door 



^^. „ Special Swing Cfieck Valve 
This Connection to be on tfie same Centre as Wet Return — — \ 



T 



Floor Line 



Z 



J=. 



/Wet Return near Floor 



5 



Fig. 6-16. Connections to an indirect radiator 
52 



called /res/t air indirect, as a constant supply of fresh heated air is dehvered 
into the room. The cold air duct is sometimes so arranged that outside air may 
be closed oflf and air taken from the basement in extreme cold weather. 

Where the air supply is taken from the room, passed over the heating 
surface and then discharged into the room again, the method is known 
as recirculatincj indirect. 

In either system no heating surface is located in the room to be heated. 

The indirect method of heating is most used in the principal rooms of 
residences, clubs, churches and similar types of buildings, and is much 
more expensive to install and to operate than is the direct system. 

All rooms heated by the fresh air indirect system must be provided 
with vents for the escape of the air replaced by that delivered by the "indirect 
stack," as this type of heating surface is often called. 

Many variable factors, each of prime importance, enter into an accurate 
calculation of the proper proportions of a system of this type. These vari- 
ables include velocity and direction of the wind, frictional resistance to the 
air flow in the ducts, and the loss of heat due to transmission through the 
walls of hot-air ducts. 

Each manufacturer of heating surface for this system has his own 
special design, which is usually sold by catalogue ratings in square feet of 
surface. Reliable data as to the free area between sections and the heating 
effect under the variable conditions of steam and air temperatures at various 
air velocities are unfortunately not available for each make of heating 
surface used in this method of heating. Proper values are very difficult to 
assign to the variable factors, and the several rules for determining the 
proper proportions of such a system are all based upon some standard 
conditions and assumptions. 

The general principle of an indirect system is the delivery of air to the 
room at a temperature higher than that of the room, and in such volume 
that in cooling to room temperature, sufficient heat units are given up to 
replace those required for transmission, infiltration and other requirements. 

The requirements for this method of heating are usually computed in 
the following way: 

First: Calculate the total heat requirements in B.t.u. per hour for the 
room to be heated as described in Chapter 5. 

Second: Determine the height of the column of heated air ; that is, the 
distance from center of indirect stack to center of the room register. 

Third: Assume the temperature of the air entering the room. This is 
usually taken about 120 deg. fahr. where air enters the radiator at zero and 
the radiator is supplied with steam at atmospheric pressure or slightly above. 

Fourth: Determine the velocity of air due to difference in densities 
between heated and outside air for columns of equal height. 

Fifth: Ascertain from the manufacturer of the selected type of heating- 
surface the velocity at which air must pass through the surface to produce 
the final required temperature , when the surface is supplied with steam at a 
predetermined temperature and air enters the heating stack at the minimum 
outside temperature. Ascertain also the temperature of the air on which 
this performance is based, the free area between the sections, and the 

5.3 



number of square feet of heating surface per section. 

The amount of heating surface may then be determined as follows: 

H = total B.t.u. losses per hour for the room. 

ti = temperature of air entering the room. 

ts = temperature of air in room (room temperature) . 

t, = temperature of air on which heating surface performance is based. 

d = density of air at temperature fc. 

V = performance velocity of air in feet per minute. 

a =free area per section of heating surface in square feet. 

none (f i \ £,0 ^ pounds of air required per minute = P 

where 0.2375 is the specific heat of the air. 
p 
T = cubic feet of air per minute at t=. 

p 

-T -^ av = number of sections of heating surface required from which 

the square feet of heating surface can be determined. 
The sizes of the ducts or flues for conveying the air to and from the 
heating surface are dependent upon the velocity of the air due to the 
unbalanced air column. This velocity may be determined theoretically 
from the formula : 

4 on /h (t — to.) 

in which ^ = ^^^^m+T 

V = velocity in feet per minute. 

h = height of warm air column in feet or distance from center of 

heating surface to center of register, 
t = average temperature of air in column, 
to = average temperature of outside air. 

To allow for friction in ducts, through heating surface, register face 
and elsewhere, velocities of one-third of the theoretical may be assumed. 
The area of the hot-air duct may be determined as follows : 

X ■ 1 144 P ' 

Area m square mches = — ^ — 

d V 

in which 

P = pounds of air required per minute. 

d = density of air at average temperature in hot-air duct. 

V = velocity in feet per minute in duct. 

The register can have a free area equal to the area of the hot-air 
duct where velocity in hot-air duet is not in excess of 300 ft. per min. For 
higher velocities the register area should be increased. The area of the cold- 
air duct can be determined in a manner similar to the hot-air duct area, 
using density of the air at the cold inlet temperature. 

Direct-indirect heating surface, as the name implies, consists of radiators 
arranged so that a portion of each serves on the indirect principle and the 
remainder as a direct radiator; the entire surface, however, is located in the 



room to be heated. This combination is accomplished by providing a direct 
radiator and installing a metal box base under some of the sections. Cold 
fresh air is taken from the outside of the building directly through the wall 
and connected to this box base. The fresh air passes up through its portion of 
the surface into the room. The balance of the surface acts as plain dii'ect 
heating surface. 

This method of heating has come into quite general use in recent years 
in some localities where the state ventilation laws for public buildings specify 
either the quantity of air to be supplied per minute per person, or the number 
of square inches of fresh-air inlet duct per person. The latter requirement 
can be met with this type of heating surface. 

The size of the opening in the wall or the wall box determines the size 
of the box base, and the number of sections of the radiator enclosed by the 
box base are to be considered as available only for heating the incoming air. 

Sufficient additional direct heating surface must be provided, either by 
adding sections to the radiator, extending same outside of the box base on 
either end, or by installing separate units for supplying the heat necessary 
for requirements of the wall, glass and infiltration, as already mentioned. 

Vent flues must be extended from all rooms heated and ventilated by 
this method. 

In order to obtain desired air movement and prevent back draft in flues, 
they must have aspirating radiation or rotary type ventilators. 

The radiation best suited for direct-indirect surface is that with high 
and wide sections. One manufacturer of the most modern devices for this 
type of system states the size of the ventilating base, together with its capac- 
ity, fresh-air inlet area and amount of radiating surface to be enclosed, as 
given in Table 6-9. 

Table 6-9. Data for Direct-indirect Heating Surface Offered by One 
Manufacturer. Not Standard for Other Similar Equipment 





Capacity 


in 


Area of fresh 




Size of wall box 


cu. ft. per 


tnin. 


air openmg 


Heating surface 


8 in. X 20 in. 


180 




120 sq. in. 


50 sq. ft. 


8 in. X 24 in. 


240 




144 


50 


8 in. X 30 in. 


300 




180 


60 


10}^ in. X 20 in. 


270 




160 


50 


lOK in. X 24 in. 


330 




192 


60 


lOM in. X 30 in. 


420 




240 


60 



As an example of selecting and computing heating surfaces, i-efer to the 
heat requirements as shown on Pages 38-39 for the various rooms in Figure 
5-1, Page 36, and assume that steam will be used at 215 deg. fahr., or 1-lb. 
per sq. in. pressure. 

Room 3 requires a total of 22933 B.t.u. per hr. and is to be heated 
by means of direct radiation. The window sills are 24 in. high. There- 
fore, 23-in. high radiators should be installed. For a room of this size, it 
appears that 2 -column radiation should give sufficient surface. The 
B.t.u. emitted by 2-column, 23-in. high radiation is given in Table 6-1 

55 



Table 6-10. Surface in Square Feet of One to Twelve ll/4-inch Pipe Coil, 

1 to 100 Feet Long 

(For other sizes of pipe, see note at bottom of next page.) 



Length 












Number of 1J4'' 


' pipes 










of coil 
in feet 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 












Square 


feet of heating surface 










1 


0.43 


0.86 


1.29 


1. 


72 2. 


15 2. 


58 3. 


01 3. 


44 3. 


87 4. 


30 4. 


73 5.16 


2 


1 


2 


3 


3 


4 


5 


6 


7 


8 


9 


9 


10 


3 


1 


3 


4 


5 


6 


8 


9 


10 


12 


13 


14 


15 


4 


2 


3 


5 


7 


9 


10 


12 


14 


15 


17 


19 


21 


5 


2 


4 


6 


9 


11 


13 


15 


17 


19 


22 


24 


26 


6 


3 


5 


8 


10 


13 


15 


18 


21 


23 


26 


28 


31 


7 


3 


6 


9 


12 


14 


18 


21 


24 


27 


30 


33 


36 


8 


3 


7 


10 


14 


17 


21 


24 


28 


31 


34 


38 


41 


9 


4 


8 


12 


15 


19 


23 


27 


31 


35 


39 


43 


46 


10 


4 


9 


13 


17 


22 


26 


30 


34 


39 


43 


47 


52 


11 


5 


9 


14 


19 


24 


28 


33 


38 


43 


47 


52 


57 


12 


5 


10 


15 


21 


26 


31 


36 


41 


46 


52 


57 


62 


13 


6 


11 


17 


22 


28 


34 


39 


45 


50 


56 


61 


67 


14 


6 


12 


18 


24 


30 


36 


42 


48 


54 


60 


66 


72 


15 


6 


13 


19 


26 


32 


39 


45 


52 


58 


65 


71 


77 


16 


7 


14 


21 


28 


34 


41 


48 


55 


62 


69 


76 


83 


17 


7 


15 


22 


29 


37 


44 


51 


58 


66 


73 


80 


88 


18 


8 


15 


23 


31 


39 


46 


54 


62 


70 


77 


85 


93 


19 


8 


16 


25 


33 


41 


49 


57 


65 


74 


82 


90 


98 


20 


9 


17 


26 


34 


43 


52 


60 


69 


77 


86 


95 


103 


21 


9 


18 


27 


36 


45 


54 


63 


72 


81 


90 


99 


108 


22 


9 


19 


28 


38 


47 


57 


66 


76 


85 


95 


104 


114 


23 


10 


20 


30 


40 


49 


59 


69 


79 


89 


99 


109 


119 


24 


10 


21 


31 


41 


52 


62 


72 


83 


93 


103 


114 


124 


25 


11 


22 


32 


43 


54 


65 


75 


86 


97 


108 


118 


129 


26 


11 


22 


34 


45 


56 


67 


78 


89 


101 


112 


123 


134 


27 


12 


23 


35 


46 


58 


70 


81 


93 


104 


116 


128 


139 


28 


12 


24 


36 


48 


60 


72 


84 


96 


108 


120 


132 


144 


29 


12 


25 


37 


50 


62 


75 


87 


100 


112 


125 


137 


150 


30 


13 


26 


39 


52 


65 


77 


90 


103 


116 


129 


142 


155 


31 


13 


27 


40 


53 


67 


80 


93 


107 


120 


133 


147 


160 


32 


14 


28 


41 


55 


69 


83 


96 


110 


124 


138 


151 


165 


33 


14 


28 


43 


57 


71 


85 


99 


114 


128 


142 


156 


170 


34 


15 


29 


44 


58 


73 


88 


102 


117 


132 


146 


161 


175 


35 


15 


30 


45 


60 


75 


90 


105 


120 


135 


151 


166 


181 


36 


15 


31 


46 


62 


77 


93 


108 


124 


139 


155 


170 


186 


37 


16 


32 


48 


64 


80 


95 


111 


127 


143 


159 


175 


191 


38 


16 


33 


49 


65 


82 


98 


114 


131 


147 


163 


180 


196 


39 


17 


34 


50 


67 


84 


101 


117 


134 


151 


168 


184 


201 


40 


17 


34 


52 


69 


86 


103 


120 


138 


155 


172 


189 


206 


41 


18 


35 


53 


71 


88 


106 


123 


141 


159 


176 


194 


212 


42 


18 


36 


54 


72 


90 


108 


126 


144 


163 


181 


199 


217 


43 


18 


37 


55 


74 


92 


111 


129 


148 


166 


185 


203 


222 


44 


19 


38 


57 


76 


95 


114 


132 


151 


170 


189 


208 


227 


45 


19 


39 


58 


77 


97 


116 


135 


155 


174 


194 


213 


232 


46 


20 


40 


59 


79 


99 


119 


138 


158 


178 


198 


218 


237 


47 


20 


40 


61 


81 


101 


121 


141 


162 


182 


202 


222 


243 


48 


21 


41 


62 


83 


103 


124 


144 


165 


186 


206 


227 


248 


49 


21 


42 


63 


84 


105 


126 


147 


169 


190 


211 


232 


253 


50 


22 


43 


65 


86 


108 


129 


151 


172 


194 


215 


237 


258 



56 



Table 6-10. Surface in Square Feet of One to Twelve 114-inch Pipe Coil, 
1 to 100 Feet Long — Continued 















Number of 


IH" pipes 










Length 


























of coil 


























in feet 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


Square feet of heating surface 


51 


22 


44 


66 


88 


110 


132 


154 


175 


197 


219 


241 


263 


52 


22 


45 


67 


89 


112 


134 


157 


179 


201 


224 


246 


268 


53 


23 


46 


68 


91 


114 


137 


160 


182 


205 


228 


251 


273 


54 


23 


46 


70 


93 


116 


139 


163 


186 


209 


232 


255 


279 


55 


24 


47 


71 


95 


118 


142 


166 


189 


213 


237 


260 


284 


56 


24 


48 


72 


96 


120 


144 


169 


193 


217 


241 


265 


289 


57 


25 


49 


74 


98 


123 


147 


172 


196 


221 


245 


270 


294 


58 


25 


50 


75 


100 


125 


150 


175 


200 


224 


249 


274 


299 


59 


25 


51 


76 


101 


127 


152 


178 


203 


228 


254 


279 


304 


60 


26 


52 


77 


103 


129 


155 


181 


206 


232 


258 


284 


310 


61 


26 


52 


79 


105 


131 


157 


184 


210 


236 


262 


289 


315 


62 


27 


53 


80 


107 


133 


160 


187 


213 


240 


267 


293 


320 


63 


27 


54 


81 


108 


135 


163 


190 


217 


244 


271 


298 


325 


64 


28 


55 


83 


110 


138 


165 


193 


220 


248 


275 


303 


330 


65 


28 


56 


84 


112 


140 


168 


196 


224 


252 


280 


307 


335 


66 


28 


57 


85 


114 


142 


170 


199 


227 


255 


284 


312 


341 


67 


29 


58 


86 


115 


144 


173 


202 


230 


259 


288 


317 


346 


68 


29 


58 


88 


117 


146 


175 


205 


234 


263 


292 


322 


351 


69 


30 


59 


89 


119 


148 


178 


208 


237 


267 


297 


326 


356 


70 


30 


60 


90 


120 


151 


181 


211 


241 


271 


301 


331 


361 


71 


31 


61 


92 


122 


153 


183 


214 


244 


275 


305 


336 


366 


72 


31 


62 


93 


124 


155 


186 


217 


248 


279 


310 


341 


372 


73 


31 


63 


94 


126 


157 


188 


220 


251 


283 


314 


345 


377 


74 


32 


64 


95 


127 


159 


191 


223 


255 


286 


318 


350 


382 


75 


32 


65 


97 


129 


161 


194 


226 


258 


290 


323 


355 


387 


76 


33 


65 


98 


131 


163 


196 


229 


261 


294 


327 


359 


392 


77 


33 


66 


99 


132 


166 


199 


232 


265 


298 


331 


364 


397 


78 


34 


67 


101 


134 


168 


201 


235 


268 


302 


335 


369 


402 


79 


34 


68 


102 


136 


170 


204 


238 


272 


306 


340 


374 


408 


80 


34 


69 


103 


138 


172 


206 


241 


275 


310 


344 


378 


413 


81 


35 


70 


104 


139 


174 


209 


244 


279 


313 


348 


383 


418 


82 


35 


71 


106 


141 


176 


212 


247 


282 


317 


353 


388 


423 


83 


36 


71 


107 


143 


178 


214 


250 


286 


321 


357 


393 


428 


84 


36 


72 


108 


144 


181 


217 


253 


289 


325 


361 


397 


433 


85 


37 


73 


110 


146 


183 


219 


256 


292 


329 


366 


402 


439 


86 


37 


74 


111 


148 


185 


222 


259 


296 


333 


370 


407 


444 


87 


37 


75 


112 


150 


187 


224 


262 


299 


337 


374 


412 


449 


88 


38 


76 


114 


151 


189 


227 


265 


303 


341 


378 


416 


454 


89 


38 


77 


115 


153 


191 


230 


268 


306 


344 


383 


421 


459 


90 


39 


77 


116 


155 


194 


232 


271 


310 


348 


387 


426 


464 


91 


39 


78 


117 


157 


196 


235 


274 


313 


352 


391 


430 


470 


92 


40 


79 


119 


158 


198 


237 


277 


316 


356 


396 


435 


475 


93 


40 


80 


120 


160 


200 


240 


280 


320 


360 


400 


440 


480 


94 


40 


81 


121 


162 


202 


243 


283 


323 


364 


404 


445 


485 


95 


41 


82 


123 


163 


204 


245 


286 


327 


368 


409 


449 


490 


96 


11 


83 


124 


165 


206 


248 


289 


330 


372 


413 


454 


495 


97 


42 


83 


125 


167 


209 


250 


ncfo 


334 


375 


417 


459 


501 


98 


42 


84 


126 


. 169 


211 


253 


295 


337 


379 


421 


464 


506 


99 


43 


85 


128 


170 


213 


255 


298 


341 


383 


426 


468 


511 


100 


43 


86 


129 


172 


215 


258 


301 


344 


387 


430 


473 


516 



Note : For all practical purposes, figure 1-3 sq. ft. of outside surface per lineal foot of 1-in. pipe ; and 1-2 sq. ft. for 1 1-2 in. pipe 



as 260 B.t.u. per hr. per sq. ft. of surface. As these radiators will be 20 
sections long instead of the standard 10, on which the above efficiency was 
based, the efficiency, or B.t.u. emitted will be reduced by 3.5 per cent, 
making an actual efficiency of 251. This divided into the total heat require- 
ments gives 91 sq. ft. of heating surface required, which is supplied by two 
units of 46% sq. ft. each as marked on the plan. 

Data as above for determination of the other units are marked on the 
plan. Room 7, which is to be heated by indirect surface, is calculated 
as follows: The total requirements for the east side are 13058 B.t.u. per In*., 
and assuming that the air enters the room at 120 deg. fahr., the pounds of 
air required in accordance with formula on Page 54 would be 18.2 per minute. 

Vento radiation 30 inches long on 4-in. centers gives a temperature 
rise of air from zero to 120 deg. fahr. at 100 ft. per min. velocity, measured 
at 70 deg. fahr. volume. The free area per section is 0.225 sq. ft. 

The pounds of air as found above divided by the density at 70 deg. 
fahr., or 0.0749, gives 244 cu. ft. of air per minute. 

This volume divided by the velocity, then by the free area per section, 
gives eleven sections required. 

The distance from the center of the radiation to the floor above is 27 
inches, which head with 120 deg. fahr. temperature difference gives a theo- 
retical velocity of 367 ft. per min., by the formulae on Page 54. For 
determining the size of the ducts, one-half of this value, or 184 ft. per min. 
velocity may be used. 

Using formula on Page 54 with a density for air at 120 deg. fahr., the 
area of the hot-air duct is 208 sq. in. The register if of 66^^ per cent 
free area should contain 312 sq. in. 

The cold-air duct by the above formula, using air density at zero, 
should have a sectional area of 165 sq. in. 

The indirect surface for the requirement of the west side of this room 
was calculated similarly. 

As another example, to determine the radiation necessary to supply the 
heat required for the factory building as calculated in the previous chapter 
and shown in Figure 5-2, Page 37. 

Assume that steam at 10-lb. per sq. in. pressure or at a temperature of 
240 deg. fahr. is available for heating this building under maximum load 
conditions. The increase in B.t.u. emission of the heating surfaces for this 
increased temperature above the standard or basic temperature is 20 per 
cent, and there would be a further increase in efficiency of 3 per cent due 
to a 65-deg. fahr. instead of 70-deg. fahr. room temperature. 

This would make a total increase of 23.6 per cent in B.t.u. emitted per 
hour per sq. ft. of heating surface for this installation, over the basic value. 

The monitor portion of the building is provided with 1 J 4-in. pipe 
coils under the windows, with expansion springs at the ends, as shown. For 
the lower portion of the building cast-iron wall surface is to be installed 
as shown. The efficiency of the heating surface and method of determining 
the amount of surface are shown on the plan. 

S8 



CHAPTER VII 

Ventilation Problems as They Affect the Design 

of Heating Systems 

VENTILATION in the past was based on more or less traditional 
and unscientific standards, but is now receiving more of the con- 
sideration warranted by its importance. 

The necessity of providing adequate ventilating facilities for public 
buildings and buildings for various classes of industrial operations has been 
recognized by the legislative bodies of numerous states and cities, which 
have passed laws and ordinances governing the quantity of air to be supplied 
per person, and in some instances also the locations from which the air supply 
is to be brought into the room and the vitiated air removed. 

Ventilation is classed, and rightly so, as a branch of applied science, 
and it is the duty of the ventilating engineer to apply the principles of this 
science to the problems with which he is dealing in such a manner that the 
results obtained will produce the most healthful and comfortable conditions 
in the ventilated rooms. 

A ventilating system may be very satisfactory in regard to the quantity 
and means of distribution of the air but still fail to produce healthful and 
comfortable conditions. A good ventilating system should produce im- 
mediate physical comfort. The human body is the best indicator as to 
whether or not these conditions are realized. 

Temperature and relative humidity are important factors in producing 
comfort; the human body is to a great extent influenced by the temperature 
of the surrounding air, and by the rate at which perspiration is evaporated 
from the body into the air, which again is influenced by the relative humidity 
of the air. 

It is generally considered that the dry-bulb temperature to produce a 
sense of comfort to a person at rest is 68 to 70 deg. fahr., provided a proper 
relation between the dry and wet-bulb temperatures is maintained. 

The human organism is very susceptible to abrupt changes such as 
might be experienced when passing from outdoors on a cold day into a 
heated room in which the relative humidity is below normal or vice versa. 

A ventilating system, to produce conditions of comfort and health, 
should therefore provide for maintaining a satisfactory relation between 
temperature and humidity. This relation, with a room temperature of 
68 to 70 deg. fahr., generally assumes a relative humidity not below 40 per 
cent, nor over 60 per cent. Although this assumption is entirely traditional, 
a relation of humidity to temperature may be found between the limits of 
which true comfort will result. 

Investigations from time to time by various engineering organizations 
and civic bodies regarding ventilating methods employed in public buildings, 
and particularly in schools, have disclosed the fact that systems of complete 
hot-blast heating and ventilation have inherent defects. Many former 

59 



advocates of this type of equipment now favor the more modern types of 
"spht system." 

It has been proved improper from the standpoint of health and com- 
fort to employ a small quantity of highly heated air to replace the heat lost 
by transmission. The air supply should be large in volume and compara- 
tively low in temperature in order to obtain the best ventilating effect. The 
nearer the temperature of the incoming air corresponds to the room temper- 
ature to be maintained, the more nearly is the ideal condition obtained. 

To compensate for the heat losses tlirough waU and glass and other 
exposures, direct radiating surface should be installed. This direct radiat- 
ing surface, if placed under the windows, will also overcome the difficulties 
due to "outside wall and window chill" which, in the hot-blast system of 
heating, has been a source of considerable discomfort. 

The close relation of ventilation and heating makes necessary a discus- 
sion as to the effect of various methods of ventilation upon the design of the 
heating plant. To illustrate these effects, some of the commonest applica- 
tions of ventilation may be classified as follows : 

The fireplace. 

Direct-indirect system of heating and ventilation. 

Indirect system of gravity ventilation. 

Ventilating systems for school buildings. 

Ventilating systems of large theatres and auditoriums. 

Ventilation of churches. 

Ventilation of banquet halls, dining rooms, kitchens, etc. 

Exhaust ventilation of industrial plants. 

Hot-blast systems of heating for industrial plants. 

The Fireplace : The purpose of fireplaces is twofold, first, ornamental 
effect, and second, utility for warming at times when the heating plant is 
not in operation. Incidentally, also, the flue or chimney of the fireplace 
acts as a vent, the chimney effect or flue draft causing continuous outflow 
of air from the room into the atmosphere. 

This outflow of air from the room through the chimney of the fireplace 
has the tendency of lowering the air temperature and pressure in the room, 
causing a greater infiltration of air from outdoors than would take place 
without the fireplace. The additional air finding its way into the room 
tends to lower the temperature, unless compensation is provided in the form 
of sufficient additional radiating surface. 

Direct-indirect System of Heating and Ventilation : This method 
of heating and ventilation, as described in Chapter 6, has come into quite 
general use in certain sections of the country for ventilating school buildings, 
public libraries and courthouses. 

Indirect System of Gravity Ventilation: Heating by the indirect 
system, in which the heat is conveyed entirely by air to the space to be 
heated, also provides a fair means of ventilation, but is open to the objection 
of highly heated incoming air. 

The amount of air to be circulated is generally stipulated, which re- 
quires knowing the temperature to which the incoming air is to be heated 

60 



so that in cooling from incoming to maintained room temperature, enough 
heat units will be provided to offset the heat losses through windows, walls, 
and other exposures. 

In designing heating plants of the indirect type, the total air to be 
circulated must be known within a fair degree of accuracy in order to deter- 
mine the quantity of steam required. 

The indirect method of heating requires from three to four times the 
quantity of steam that would be needed with direct radiation for the same 
warming effect. This indicates the importance of carefully considering 
ventilating problems in connection with heating systems, in order to determine 
proper proportions for boilers, pipes, radiator supply valves, return traps, 
and any other heating system apparatus which would be affected by the in- 
creased steam requirement due to the ventilating equipment. 

With the indirect system it is also necessary to provide aspirating 
radiators in the vent flues. 

The method of computing indirect radiating surface for given heating 
effects and requirements is discussed in Chapter 6. 

Ventilating Systems for School Buildings: The direct-indirect 
and the indirect systems of heating previously mentioned are frequently 
used for ventilating school houses of the smaller type, but for buildings of 
larger proportions mechanical systems of ventilation are generally installed. 

The necessity for healthful and comfprtiible conditions in school build- 
ings has been the main stimulus for enacting ventilating laws by various 
states and cities. 

Great progress has been made in late years in the design of ventilating 
plants for school buildings. The antiquated hot-blast system of heating 
and ventilation without provision for humidification has been almost 
entirely abandoned and superseded by the modern split-system method of 
ventilating with tempered air, washed and humidified before being delivered 
into the rooms. Direct radiation is installed for taking care of the heat lost 
through direct exposures of walls, windows, doors, etc. 

Ajr is generally supplied to the class rooms through registers or dif- 
fusers placed at a level of seven to eight feet above the floor with the vent 
registers near the floor. The most satisfactory arrangement is generally 
obtained where the heat and vent flues are placed in the corridor walls and 
the air is blown towards the windows. The vitiated air is discharged from 
the vent flues into ventilators in the roof to the atmosphere. 

The cold air intake should preferably be at a point above the roof. 
The intake openings are dampered, and additional air intake openings are 
provided in the attic space, making the re-circulation of air from the building 
possible during the heating-up period in the morning. Delivering the air 
into the rooms at nearly the temperature to be maintained and with auto- 
matic temperature control or modulation supply valves on the direct radia- 
tors, gives ideal conditions as near as obtainable. 

In computing the requirements for direct heating in the ventilated spaces, 
it is only necessary to take into account the heat losses due to exposures. 
Exceptions, however, must be made of rooms which are to be in use after the 
ventilating system is shut down, such as libraries, reading rooms and offices. 

61 




Fig. 7-1. Arrangement of fresh air inlet with diffusers, vent outlet and direct radiators 

in a modern school room 



Ventilating systems of school buildings are usually shut down after 
the close of the afternoon session. Any rooms that may be in use after 
that period should have sufficient direct radiation to take care of the maxi- 
mum requirements without the assistance of the ventilating system. 

The steam required to temper the air needed for the ventilating system 
is generally greatly in excess of that required for the direct system of 
heating. 

Where air washers and humidity -control systems are installed, addi- 
tional steam is required to add to the heat in the air, compensating for the 
drop in temperature in passing through the air washer and to supply the 
humidity control apparatus. 

Masonry ducts under floors, if used for the main trunk supply system 
for air distribution, should be so constructed that they can be kept dry at 
all times. This can be accomplished by the use of a reliable system of 
waterproofing. The cooling effect of these masonry ducts must be considered 
in the design of heating and ventilating plants and during the heating-up 
period sufficient time should be allowed for heating the ducts thoroughly. 

The entire heating plant, including boilers, vacuum pumps, piping 
system and direct radiation, is affected by the method of ventilation. In 
the design of the plant all phases of the application and operation of the 
ventilating system must therefore be known and analyzed to make possible 
a well balanced system. 

62 



Ventilation of Theatres and Auditoriums: The ventilation of 
theatres and auditoriums presents an entirely different problem from that 
encountered in the ventilation of a building subdivided into a number of 
comparatively small rooms. 

The problem of proper air distribution in large spaces with seating 
capacities numbering into thousands requires special study to provide 
the required quota of fresh air for each occupant. 

Ventilating systems for theatres and auditoriums are usually operated 
only during the performances, so that portions of the structure which are in 
use at other times should be heated by direct radiation. 

The quantity of air supphed to theatre auditoriums, on the basis of 
30 cu. ft. per min. per occupant, is usually so large that sufficient heat 
is supplied by delivering the air into the space at a temperature a few 
degrees higher than that to be maintained. The temperature regulating 
system should be flexibile enough to automatically reduce the incoming 
air temperature when a large percentage of the seats are occupied, and in this 
way prevent excessive temperature rise in the room. 

The modern theatre would not be complete without the installation of 
air washers, humidity-control system, and, for summer use, a refrigerating 
system for cooling the air. 

The design of heating and ventilating systems for large auditoriums 
presents an interesting problem in engineering. One is so closely affected 
by the other that both should be worked out together so that the results 
obtained will harmonize. 

Ventilation of Churches: Ventilation for churches is usually 
applied only to the main auditorium and Sunday-school room, the balance 
of the building being heated by direct radiation. Most churches are not 
continuously heated, and the warming-up period should on that account 
receive careful consideration by the designer. The ventilating system is 
generally operated during the Sunday services only. 

Whether to use the up-flow system of air distribution or to discharge 
the air into the room through registers in the wall will greatly depend on the 
size of the room to be ventilated. In large churches, a combination of both, 
blowing in the air partly through openings in the floors in the aisles, and partly 
through registers in the walls, will give good results. Vent openings are 
usually placed in the walls near the floor and in the ceihng. 

The ventilating system for a church should supply air for ventilation only 
and no attempt should be made to use the fan system for heating. For 
satisfactory results, sufficient direct radiation should be provided to com- 
pensate for all heat losses due to direct exposures and infiltration. Arrange- 
ment for re-circulating the air before the building is occupied will be found a 
convenience, both from the standpoint of shortening the warming-up period 
and also of effecting a considerable economy in the fuel consumption. 

It is considered good practice to have a separate boiler and piping 
system for that part of the heating and ventilating plant which will be in use 
Sundays only, having another boiler to heat the portions of the church in 
use during week days. 

63 



Ventilation of Banquet Halls, Dining Rooms, Meeting Rooms, 
Etc. : In no other class of ventilated rooms is the efficiency or inefficiency 
of the ventilating system so noticeable as in banquet halls, dining rooms and 
meeting rooms. Smoke-laden air indicates that the ventilating system is 
not functioning properly, while if the air is clear and fresh in spite of smoking 
by the guests, a satisfactory diffusion of air in the room is shown. 

As already pointed out in connection with other ventilating problems, 
the air should be brought in as nearly at room temperature as possible, and 
if heating of the room involves consideration of outside exposures, direct 
radiation should be used. The location and distribution of the exhaust open- 
ings is of prime importance and the exliaust should be accomplished by 
mechanical means. Vent openings should be placed near both floor and 
ceiling, and, if the structural conditions permit, additional vents should be 
provided in the ceihng toward the center of the room. 

Kitchens require a very large air change, which should be accomplished 
by means of exhaust fans. Ordinances of some cities specify a three-minute 
air change for hotel kitchens, requiring a separate steel vent stack to be 
extended through the roof for this purpose. An exliaust fan, with inlet 
connected to this vent shaft, is usually placed in the penthouse. Above the 
point where the fan inlet connection is made, a tight-fitting damper propped 




Anale Iron Frame bolted 
to Duct and anchored to 
Brickwork 



Steel Plate Fire Damper 



7-2. Arrangement of fan, vent stack and safety damper of ventilating equipment for a kitchen 

64 



open with bar iron having a fusible hnk is placed in the vent shaft, and the 
fan discharge is reconnected to the vent shaft above this damper. In case 
the fusible link is melted, the damper in the fan intake drops by gravity, 
closing the fan inlet and the stack is opened to the atmosphere. This 
permits the stack to burn out without damaging the exhaust fan. 

Where kitchens adjoin the dining rooms, the latter can conveniently 
be exliausted through the kitchen. This greatly reduces the inflow of air 
from outdoors into the kitchen and at the same time prevents odors from 
the kitchen from flowing into the dining room. 

Where existing conditions do not permit induction of air from warmed 
spaces to replace that exhausted, the air must necessarily find its way into 
the kitchen from outdoors and provision must be made to prevent a drop 
below the desired temperature. This is best accomplished by installing 
direct or indirect radiation for heating to the temperature needed. 

Considerable heat is produced by the ranges and steam cooking utensils, 
so that the kitchen may be overloaded with radiation unless complete in- 
formation is available as to the kitchen equipment to be used. 

Exhaust Ventilation of Industrial Plants: Industries, which in 
their operations produce dust, acid fumes, or in any other way contaminate 
the air, require positive means for removing the dust or fume-laden air from 
_ the premises. Mechanical systems of exhaust ventilation are 
used to maintain a continuous air change by exhausting the 
dust-laden air. 

Various types of machines, such as grinders, buffers and 
wood-working machines, are provided with sheet-metal ducts 

running to the exhaust fans, 
which are usually centrally locat- 
ed, and discharge either into 
dust-collecting chambers or into 
the atmosphere, depending upon 
the nature of the dust or refuse 
to be handled. 

The continuous exhausting 
of air from any space will cause 
a corresponding inflow of out- 
door air which must be heated 
to avoid lowering the inside 
temperature. 
If the ventilated spaces have out- 
side exposures, the air is drawn directly 
from outdoors, and infiltration takes 
place uniformly ovev the entire exposed 
area. A sufficient amount of direct heat- 
ing surface to heat this air to the temper- 
ature to be maintained must be added to 
the heating surface required for heating 
the space without the exhaust system. 




Fig. 7-3. Indirect radiation con- 
nected for air supply through a wall. 



65 



The use of large indirect radiation connected for air supplj^ through 
window or other opening in outside wall, as shown in Fig. 7-3, has been found 
in practice to be an excellent method for Avarming the infiltrated air necessary 
to replace that remoA'ed by an exhaust fan system. In connection with 
temperature control of the warmed air this method has proved highly 
efficient. 

If, however, the ventilated space has no direct exposure and connects 
with other rooms so that the air will be drawn from these, the additional 
radiation must be placed in the rooms from which the air is drawn or indirect 
inlets must be provided. 

Chemical plants requiring the removal of acid fumes must usually 
exliaust large volumes of air from the rooms, and an equivalent quantity 
of air must be admitted directly from outdoors. This air is generally ad- 
mitted through special openings in the walls and is drawn through tempering 
coils, so that it enters the room at the temperature to be maintained. In 
such cases the heating-up requirement can be eliminated from the heat loss 
calculations, and the direct radiation should be sufficient only to compensate 
for the losses through direct exposures and infiltration. However, where 
the exhaust system is in use only at intervals, allowances for heating up 
the contents of the room should be made in figuring the warming-up period. 
Sufficient direct radiation should be added to su23ply the heat units required 
for this purpose. 

Hot-blast Systems of Heating for Industrial Plants: In indus- 
trial structures, such as large foundries, machine shops, erecting shops and 
round-houses, the hot-blast system of heating, instead of the direct method, 
is often selected, owing to its lower first cost. From the operating stand- 
point, however, the hot-blast system is considerably more expensive than 
the direct, because of the greater amount of steam required for heating by 




1''ig. 7-4. Arrangement of hot-air ducts of hot-blast system in an industrial plant. The side walls are 
protected by direct radiation placed under windows 



any indirect method. This condition is particularly apparent in cases where 
all the air is taken directly from outdoors and after being circulated through 
the space is discharged into the atmosphere. 

Where air can be taken from the space to be heated and re-circulated, 
instead of taking it from outdoors, the steam requirements are considerably 
reduced. In either case, the air must be heated at the fan to such a tem- 
perature that in cooling from the air-outlet temperature to that maintained 
inside, all heat losses are offset under maximum conditions. 

Only a few general ventilating problems and their direct effect upon 
heating plant design have been mentioned in this chapter, but these show 
the importance of analyzing each problem thoroughly and making all 
necessary provisions for the ventilating system in heating system design. 

Factors Entering Design of Complete Heating and 
Ventilating Plant 

Air Quantities Required for Ventilation: Air quantities in many 
states and municipalities are fixed by legal restrictions which must be followed. 
However, some of the generally accepted standards are mentioned here. 

The type of building and the purpose for which it is to be used are the 
main factors entering into the design of any ventilating system, not only 
as to the type of ventilation Avhich is best adapted to each particular problem, 
but also as to the volume of air required. 

Tables 7-1, 7-2, and 7-3 list kinds of buildings, together with their air 
requirements and allowable air velocities. These quantities, with slight 
variation, have been universally adopted. 

Table 7-1. Air Requirements of Various Buildings 

Type of building Air supply. Cu. ft. per occupant per hr. 

School buildings 1800 

Theatre and assembly halls 1500 

Churches 1500 

Prisons 2100 

(Ordinary 2600 

Hospitalsmounded 3500 

[Contagion 6000 

Residence 1600 to 2000 

Factories 2000 to 3000 

Table 7-2. Allowable Air Velocities. Public Building Work. Fan Systems 



Supply air Exhaust air 

Cold-air intake 700-1000 ft. per min. Register outlets 300-400 ft. per min. 

Cloth filters About 40 " " " Vertical flues (masonry) 400 " " " 

Air washers 500 " " " Vertical flues (sheet-metal) 500 " " 

Indirect heaters (Vento) 800-1200 " " " Horizontal ducts 600 " " 

Horizontal air ducts 1000-1200 " " " at far end up to 1000 at 

at fan, decreasing to 600 fan inlet. 

ft. at base of flues. Fan discharge outlet 700-1000 ft. per min. 

Verticalflues (masonry) 500 ft. per min. 

Vertical flues (sheet-metal) 600 " " 

Register outlets 200-300 " " 

For air outlets 15 ft. or more above floor velocity 
may be as high as 350 ft. per min. if not thrown 
directly down on persons below. 

67 



Table 7-3. Allowable Air Velocities in Various Buildings in Feet per Minute 



Horizontal 
ducts 



Vertical 
risers 



Outlets 



Factories 1500 to 2800 

Schools 1000 to 1800 

Hospitals 1000 to 1800 

Theatres 1000 to 1800 

Churches 1000 to 1800 



900 to 1500 
500 to 750 
500 to 750 
500 to 750 
500 to 750 



600 to 1200 
300 to 500 
300 to 600 
300 to 600 
300 to 600 



Sizing of the Ducts : Two methods of estimating are in common use : 

First, the velocity method, in which the velocity is fixed in the various 
portions of the system, and decreases from the fan outlet to the various 
points of discharge. This method is applicable in single-duct systems and 
in public buildings layouts, where the law requires certain velocity standards. 

Referring to the duct design in Fig. 7-5, certain volumes and velocities 
are given. To determine the size of ducts at any particular point, the vol- 
ume in cubic feet of air passing that point is divided by the velocity in feet 
at that point, which gives the required area in square feet. 

Determination of the friction in any part of the duct is made by 
reference to the friction chart. Figure 7-7. 

In a single-duct system, the longest 
duct, or the duct requiring greatest pres- 
sure, should be designed for certain veloci- 
ties and the total pressure required at the 



900'Vel.- 



,5J Sq. Ft. Free Area 



4f Sq. Ft. Free Area 




1200 Cu. Ft. 



1200 Cu. Ft. 



"^ 






^ 



~2tSq. Ft. Free Area 



1200'Vel. 



lOOU'Vel. 



Fig. 7-5. Arrangement of 
ducts in a trunk-line system. 
Sized by the velocity method 



900 Vel.- 



-900 Vel. 



-1-ISq. Ft. Free Area 



3:=^ 



1200 Cu. Ft. 



1500 Cu. Ft. 



1200 Cu. Ft. 



plenum chamber determined from the friction chart, Figure 7-7. All other 
ducts should then be designed for the same pressure. 

Second — The friction-loss method, in which the duct is proportioned 
for equal friction pressure loss in every foot of run. 

This method of duct sizing necessitates assumption of the velocity 
and volume at the outlets, and is adaptable to trunk-line duct systems such 
as are common in factories. 

Table 7-4 gives an easy and accurate method for sizing ducts by pres- 
sure loss method. An example of its application follows (See Figure 7-7) : 

Assuming a 1000 cu. ft. discharge from each outlet at 1000 ft. velocity 
per mill, the area of the outlet is 1 sq. ft. or say 14 in. in diameter. 

Referring to Table 7-4, a 14-in. pipe is equivalent to 737 1-in. pipes 



68 



29 — 



/' 


1000 Cu. Fl. 


1000 Cu. Ft. 


1000 Cu. Ft. 




\^ 


(l 


/ 


1000 Cu. Ft. 


1000 Co. Ft. 


1000 Cu. Ft 



39, 



T 



"^ 



Velocity at Outlets, 1000 Ft. per Min. 




Fig. 7-6. Arrangement of chicts in 
a trunk-line system. Sized by the 
pressure-drop method 



and two 14-in. pipes are equivalent to 1474 1-in. pipes. AJso, 1474 1-in. 
pipes are equivalent to approximately a 19-in. pipe, and so on. To deter- 
mine velocity at any point, the volume there is divided by the area in sq. ft. 
To determine friction in any portion of duct refer to Fig. 7-7. 

Calculation of Resistance or Pressure: It is not the intention 
to go into the many complex formulae entering into the loss of pressure 
in ducts but rather to arrange some easily workable method. 

Table 7-4. Comparison of the Air-carrying Capacity of Various Sizes of Pipes 
with That of a 1-in. Pipe of Same Length and Equal Friction Pressure Loss 

Example — With an equal pressure loss and equal length, a 4-in. diameter pipe wiU carry the same 
volume of air as thirty-two 1-in. pipes. 



Diam. 


1" Pipes 


Biam. 


1" Pipes 


Diam. 


1" Pipes 


Diam. 


1" Pipes 


Diam. 


1" Pipes 


I 


1 


21 


1985 


41 


10565 


61 


28850 


81 


.59122 


9 


5 


99 


2250 


42 


11300 


62 


30200 


82 


60831 


3 


16 


23 


2525 


43 


12030 


63 


31350 


83 


62540 


4 


32 


24 


2800 


44 


12621 


64 


32500 


84 


64249 


5 


56 


25 


3060 


45 


13400 


65 


33975 


85 


66396 


6 


88 


26 


3425 


46 


14100 


66 


35300 


86 


68542 


7 


129 


27 


3738 


47 


1.5000 


67 


36600 


87 


70687 


8 


180 


28 


4100 


48 


15850 


68 


38000 


88 


72833 


9 


244 


29 


4440 


49 


16610 


69 


39275 


89 


74979 


10 


317 


30 


4898 


50 


17600 


70 


40250 


90 


77125 


11 


402 


31 


5312 


51 


18275 


71 


41995 


91 


79271 . 


12 


501 


32 


5631 


52 


19335 


72 


43740 


92 


81416 


13 


613 


33 


6154 


53 


20000 


73 


45449 


93 


83562 


14 


737 


34 


6675 


54 


21500 


74 


47158 


94 


85708 


15 


876 


35 


7075 


55 


22300 


75 


48887 


95 


87854 


16 


1026 


36 


7735 


56 


23450 


76 


50576 


96 


89999 


17 


1197 


37 


8265 


57 


24500 


77 


52285 






18 


1375 


38 


8715 


58 


25600 


78 


53995 






19 


1580 


39 


9350 


59 


26700 


79 


55704 






20 


1775 


40 


10060 


60 


27700 


80 


57413 







69 



The friction chart, Figure 7-7, (based on accepted pressure loss formu- 
lae) provides quick, accurate determination of pressure loss. 

Example: Assume that 30000 cu. ft. of air per minute is passed through 
a duct 40 in. in diameter and 50 ft. long. From the 30000 cu. ft. division 
at the right of chart, trace horizontally to intersection with the line repre- 
senting 40 in. diameter pipe. PeriDendicularly down from this point the 



o o oooooo 




Friction in Inches Water Gauge per 100 Feet 



Fig. 7-7. Chart for determining pressure loss in ducts 
70 



Table 7-5. Resistance of 90-des. Elbows 



Radius of throat 

of elbow in 

diameters of 

pipe 



Number of diameters 

of straight pipe 

offering equivalent 

resistance 



Radius of throat 

of elbow in 

diameters of 

pipe 



Number of diameters 

of straight pipe 

offering equivalent 

resistance 



1 . 



.67.0 
.30.0 
.16.0 
.10.0 

'. 6^1) 
. 5.0 
. 4.3 



-2V2 

3 


4.5 

4.8 


SW 


5.0 


4 


5.2 


4.1/^ 


5.5 


5 


5.8 


S'/Q 


6.0 



friction in inches of water per 100 ft. of pipe is given — in this case 0.54 inches. 

For 50 ft. the friction will be 50 per cent of 0.54 or 0.27 in. of water. 
Friction in inches of water multiplied by 0.58 gives friction in ounces. 

The resistance (Table 7-5) is expressed as that of the number of diameters 
of straight pipe of same diameter as the elbow, and is given for elbows hav- 
ing different radii of throat, also expressed in diameters of pipe. For instance, 
a 90-deg. elbow of 24-in. pipe, having a radius of throat equal to 1 diameter, 
that is 24 inches, offers the same resistance to the flow of air as 10 diameters 
of straight pipe or 20 ft. of straight pipe. 



n 








Ratio of Ion 


g sid 


of rectang 


ul 


r duct to diameter 


of Roun 


hpe 


fiaving 


lame 


resistance for same 


cu 


. ft. per 


mm. 


A 


■^U 
















— -i 














r 




r\ 










































































/ 
























B 














'■-^ 


U^ 


^ 








































































/ 












t 




<- 


-A 


^ 


* 






^ 










































































/ 






































































































/ 






































































































/ 




















:q 


J IV 


ale 


nt Duct 


:u 


ve 




































































/ 






































































































/ 






































































































/ 






































































































/ 






































































































/ 






































































































/ 
























7 














































































/ 




































































































/ 


























c 












































































/ 






































































































/ 
































6 






































































/ 


































































































/ 


/ 


































c 


































































/ 






































































































/ 










































5 




























































/ 










































c 


























































/ 








5 , 






































































/ 




















c 






















































/ 














A 




/(4-f+(if 












c 
r 




















































/ 
















D ~ 














'_ 
















































i 


y' 












































































/ 






















1 "■'"' 












. 












































> 




























































C 


3 






































<' 


/" 


































































































/ 




































































































^ 










































h 
























































^ 


y 










































































2 


























/ 


































































































^ 


^ 


































































































^ 






































































































^ 
























































































1 










^ 


^ 
































































































^ 










































































































































































































































































































































_^ 




L. 













































































0.; O.S 0.0 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 l.S 1.9 



2.0 



2.0 3.0 3.1 3.2 



Fig. 7-8. Curve for determining the diameters of round pipes having the same friclion loss for 
same capacity as rectangular ducts of various dimensions 

71 



To the resistance of the duct system should be added the resistance 
through tempering and reheating coils, also air washers, plus a small factor of 
safety, thereby determining the total pressure against which the fan must 
deliver the specified volume of air. 

Where each branch duct leaves the trunk line, there should be a volume 
damper with trunnion, quadrant and locking device, for balancing the system. 

Figure 7-8 is a curve for determining diameter of round pipe having 
same friction for same capacity as rectangular ducts of varying dimensions. 

Selecting the Apparatus 

Sizes and Arrangement of Fans: For fan performances and capaci- 
ties, reference should be made to tables issued by the manufacturers. 

Table 7-6. Quantities of Air at Various Temperatures Which Will Be Raised 

1 deg. fahr. by 1 B.t.u. 

At zero 1 cu. ft. of dry air weighs 0.0864 lb. and 



lib. 
.0864 



Specific heat of air at constant pressure is 0.2375 

= 11..574 cu. ft. ^^^ = 48.74 cu. ft. raised 1 deg. by 1 B.t.u 



Temp. 


Weight 




Cu. ft. 1 


Temp. 


Weight 




Cu. ft. 1 


Temp. 


Weight 




Cu. ft. 1 


air deg. 


of 1 


Cu. ft. 


B.t.u. will 


air deg. 


of 1 


Cu. ft. 


B.t.u. will 


air deg. 


of 1 


Cu. ft. 


B.t.u. will 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 





. 0864 


11.58 


48.74 


72 


. 0747 


13.39 


56.40 


152 


. 0649 


15.40 


64.90 


12 


. 0842 


11.87 


.50.00 


82 


.0733 


13.64 


.57.40 


162 


.0638 


15.65 


66.00 


90 


, 0824 


12.14 


51.00 


92 


.0720 


13.90 


58.60 


172 


.0628 


15.90 


67.00 


32 


.0807 


12.40 


52.20 


102 


.0707 


14.14 


59.20 


182 


.0618 


16.17 


68.00 


42 


.0791 


12.64 


.53.10 


112 


. 0694 


14.40 


60.60 


192 


.0609 


16.42 


69.10 


.52 


.0776 


12.88 


54.10 


122 


. 0682 


14.65 


61.60 


202 


.0600 


16.67 


70.10 


62 


.0761 


13.13 


55.20 


132 


.0671 


14.90 


62.80 


212 


.0591 


16.92 


71.30 


70 


. 0750 


13.34 


.56.30 


142 


.0660 


15.15 


63 80 











Heaters : To select a heater for any set of conditions it is necessary to 
know the volume of air to be handled, its initial temperature, and the 
temperature to which it must be raised. 

Two methods for detennining the above quantities are available 
where the building is heated as well as ventilated by the air. One applies 
where a definite air change is desired or where ventilation must be provided 
for a given number of people. 

Example: Assume a building requiring 18000 cu. ft. per min. measured 
at 70 deg. fahr. with a total of 860000 B. t. u. loss through exposed glass, walls, 

B.t.u. loss per hr. 



etc. Then 



Cu. ft. per min. X .2375 X 
860,000 



diffusion 



.075 X 60 

45 deg. fahr 



18000 X .2375 X .075 X 60 
45 deg. diffusion + 10 deg. duct loss + 70 deg. desired room temperature = 
125 deg. final temperature at coils. In this calculation 0.2375 is the specific 
heat of air and is constant and 0.075 is the weight of one cubic foot of air 
at the room temperature of 70 deg. (See Table 7-6.) 

The other method is to decide on the final temperature to be used with 
some fixed entering temperature. 



72 



Example: Suppose the hourly heat loss through exposed walls, glass, etc., 
is 1204500 B.t.u. Assume a final temperature at the heater of 135 deg. 
fahr. and a loss of 10 deg. in the ducts. The temperature at the duct 
outlets will then be 125 deg. fahr. The room temperature desired is 65 deg. 
and the outside temperature is deg. 

The difference in the temperature between the duct outlets and the 
room temperature is available for heating. 

(^ . . _ B.t.u. per hr. _ 1204500 

u. . per mm. ^^ ^^ ^^ ^ ^^^^^ ^ ^^^ 60 X 60 X .2375 x .068 

20720 cu. ft. per min. required, in which 0.2375 is specific heat of air and is 
constant and 0.068 is weight of one cu. ft. of air at 125 deg. (See Table 7-6.) 

Either of the above formulae can be used on split systems where a 
portion of the losses through walls, glass, etc., are taken care of by direct radia- 
tion, and the balance by the incoming air. In the split system where all 
heat loss through walls, glass, etc., is taken care of by direct radiation, the final 
temperature of the air is, of course, the same as the room temperature de- 
sired. However, in choosing the heater, allowance should be made for some 
temperature drop in the ducts (usually 10 to 20 degrees). 

After determining the volume and final temperature of the air the size 
of heater can readily be chosen from tables furnished by manufacturers. 

Table 7-7. B.t.u. Required for Heating Air* 

This table specifies the quantity of heat in B. t. u. required to raise 1 cu. ft. of air through any 
given temperature interval 

Temperature of air in room, deg. fahr. 



External 
Temp. 


40° 


so° 


60° 


70° 


80° 


90° 


100° 


110° 


120° 


130° 


-40° 


1.802 


2.027 


2.2.52 


2.479 


2.703 


2.928 


3.1.54 


3.379 


3.604 


3.829 


-30° 


1.540 


1.760 


1.980 


2.200 


2.420 


2.640 


2.860 


3.080 


3.300 


3.520 


-20° 


1.290 


1.505 


1.720 


1 . 935 


2.150 


2.365 


2.. 580 


2.795 


3.010 


3.225 


-10° 


1.051 


1.262 


1.473 


1.684 


1.892 


2.102 


2.311 


2.522 


2.732 


2.943 


0° 


0.822 


1.028 


1 . 234 


1.439 


1.645 


1.851 


2.0.56 


2.262 


2.467 


2.673 


10° 


0.604 


0.805 


1.007 


1.208 


1.409 


1.611 


1.812 


2.013 


2.215 


2.416 


20° 


0.393 


0.590 


0.787 


0.984 


1.181 


1.378 


1 . 575 


1.771 


1.968 


2.165 


30° 


0.192 


0.385 


0.578 


0.770 


0.963 


1.155 


1.345 


1.540 


1.733 


1 . 925 


40° 


0.000 


0.188 


0.376 


0.564 


0.752 


0.940 


1.128 


1.316 


1.504 


1.692 


50° 


0.000 


0.000 


0.184 


0.367 


0.551 


0.735 


0.918 


1.102 


1.286 


1.470 


60° 


0.000 


0.000 


0.000 


0.179 


0.359 


0.538 


0.718 


0.897 


1.077 


1.256 


70° 


0.000 


0.000 


0.000 


0.000 


0.175 


0.350 


0.525 


0.700 


0.875 


1 . 049 



*F. BahMYnamns Manual of Heaiimj and Ventilation. 

Boiler Horsepoaver Required : To determine the boiler horsepower 

required for air heating, the following formula can be used: 

Cu. ft. per min. X 60 X A ^^ . i 

~ ^ = lb. steam per hour. 

B 

in which A = B.t.u. required for heating 1 cu. ft. of air from initial to 

final temperature (See Table 7-7). 

B = latent heat of steam 

lb. steam per hr. i -i , 

qi~r^ ^ boiler horsepower 

From the manufacturers' tables the condensation rates per square foot 
of surface are given for various velocities and temperatures, and it is well 
to check up the above formula from these given factors. 

73 



CHAPTER VIII 



Proportioning of Chimneys 

"VTO problem in the heating of buildings presents greater elements of 
\ uncertainty than that of projDerly proportioning the chimney. 

In larger installations, such as isolated plants for the production 
of power, light and heat, the conditions may usually be very accurately 
determined in advance. By use of the formula given hereafter, proper 
results follow in almost every case. 



A. Chimneys for House-Heating Boilers 

In small plants and particularly residence heating, it is not practicable 
to make such accurate advance determinations of all the conditions. Usually 
the chimney is built into the wall, thereby requiring that its cross-section 
must be proportioned to the width of brick. Chimneys so built are usually 
either smoothly mortared on the inside or lined with thin tile of rectangular 
or circular cross-section. The latter 
gives such freedom from friction and 
eddy currents and lessened surface for 
loss of heat in the gases, that a round 
chimney lining will frequently give 
fully as good results as would be ob- 
tained in the square of brick-work in 
which it is enclosed. 

The inclination to cut down cross- 
sectional area to save cost and space 
in the portion of building through 
which the chimney passes should be 
discouraged as false economy. Once the chimney is built into the structure, 
increase of area is practically impossible, and a chimney that is too small 





















Fig. 8-1. 



Cross-sections through typical house 
chimneys 



-169i- 



678' 



Inside Area equals 
80 sq.ins. 



11!4 



-13— 



Inside Area equals 
188 sq.ins. 



■/.■/^^//y^//y^y^^/^/V^/^^^/>M/y^^^^'/y'A 



Fig. 8-2. Seven bricks per course 



Fig. 8-3. Nine bricks per course 



74 



remains a source of discomfort and waste during the entire life of the struc- 
ture. Little is saved in building an 83/2-"i- by 13-in. flue as compared 
with a 13-in. by 18-in. flue, the latter having more than twice the area and 
more than twice the capacity, while the bricks per course are as 9 is to 7. 
(See Figures 8-2 and 8-3.) 

To get the greatest efli"ectiveness, a definite amount of draft must be 
available. The actual amount required varies widely for different types of 
commercial cast-iron boilers, and, unfortunately, it is not always possible 
to know in advance which make of these boilers will be selected or may 
later be installed. It is, therefore, preferable to provide for excessive draft 
which may be controlled by damper, rather than to risk insufficient draft, 
the remedying of which is almost hopeless. 

For ascertaining the probable interior cross-section of round or rectan- 
gular flue linings, also unlined brick chimneys necessary for average cast-iron 
heating boilers where height in feet from combustion chamber to top of 
chimney and maximum hourly rate of evaporation in pounds of water are 
known. Figures 8-7a and 8-7b will be found convenient. 

With the maximum rate and height of chimney determined, enter the 
table at right-hand column at the determined hourly evaporation rate ; fol- 

Table 8-1. Dimensions of Flue Linings 



Fig. 8-4 



U 



Fig. 8-5 




Fig. 8-6 























As mauu 


'actured by 






















The Delaware Clay Products Co. 




W. S. Dickey Clay Mfg. Co. 




Robinson Clay Products Co. 


Pittsburgh, Penna. 




Kansas City, Mo. 




Akron, Ohio 




Rectangular 
and square 


Circular 




Rectangular 
and square 


Circular 


Rectangular 
and square 


Circular 


Sq. 










Sq. 






Sq. 






1 


Sq. 






Sq. 










Sq. 






m. 










m. 






m. 










m. 






m. 










in. 






free 


A 


B 


C 


D 


free 


E 


F 


free 


A 


B 


C 


D 


free 


E 


F 


free 


A 


B 


C 


D 


free 


E 


F 


area 


3H 


7K 


4^ 


SK 


area 
2S 


6 


714 


area 










area 






area 










area 






23 


29 


334 


734 


4V^ 


&V, 








23 


314 


7 


434 


8H 


28 


6 


714 


36 


■m 


uy. 


4J/, 


13 


3S 


7 


SH 


61 


VH 


■/^ 


SM. 


S'/, 








36 


■i^ 


1134 


434 


13H 


38 


V 


■6V, 


47 


2i/, 


IB^s 


4U 


IX 


.^0 


X 


9U 


46 


■AH 


1214 


4 I/O 


13 








60 


■i'/» 


lo'/o 


41/, 


17 


50 


S 


9 


39 


6H. 


6M 


7M 


TA 


64 


9 


10 li 


92 


7H 


VZVa 


8i4 


13 








47 


4^2 


lOM 


6 


12 


64 


9 


10^2 


52 


T^ 


7A 


8H 


SU 


78 


10 


nv. 


145 


ISt^b 


12A 


13 


13 








33 


534 


534 


7¥ 


^Vi 


78 


10 


12 


SU 


B-hi 


11 ,> 


XU 


13 


113 


12 


14 


127 


TV, 


I6V, 


XU 


17'/, 


125 


12'^ 


UH 


52.5 


■iv^ 


V'4 


SH 


S'/o 


113 


12 


14 


IIU 


(i%( 


IBM 


X'/o 


IX 


176 


15 


1714 


202 


12H 


16 H 


13 


171/0 








80 


6''/, 


113/a 


■&V-, 


13 


176 


15 


17 V« 


129 


iiH 


IIH 


13 


13 


254 


18 


20H 


270 


IBlV 


16A 


171/2 


17^2 








104 


6i/2 


16 


8H 


IS 


254 


IS 


20>^ 


188 


11 "4 


1634 


13 


IS 


314 


20 


2234 












291 


1914 


21U 


127 


\\-Vi 


11« 


13 


13 


314 


20 


23 


26ti 


i(> 


16 


IX 


IS 


3SI) 


22 


25 M 


















169 


1034 


lb3/( 


13 


IS 


346 


21 














452 


24 


27M 












499 


^5iV 


27^ 


240 


15H 


loM 


IS 


IS 


380 
452 

572 

707 

855 

lOlS 


22 
24 

27 
30 
33 
36 


27 
35 



Note. All dimensions are in iaches and subject to slight variation 

75 





TYPES 


OF CHIMNEY CONSTRUCTION 








1 












/i/\A/ 




Rectangular Tile Circular Tile Ruueh Brick 

(T^ ^^ 






















/' ' 


^ / 


























/ 


/ 


/ 






1 ^— ^^— ' 1 
























/ 


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SIZES OF CHIMNEYS 












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Inside dimensions in inches 












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Fiff. 8-7a 



30 40 50 GO 70 SO 00 100 

FEET IN HEIGHT BETWEEN COMBUSTION CHAMBER 

AND TOP OF CHIMNEY 



IJOO 
UJO 
1400 

1350 

1300 

1250 

1200 

1150 

1100 

1050 

1000 

950 

900 
o= 

850 o 

zr. 

800^ 

(OO LU 

700 fe 

CO 

050^ 

CD 

GOO 
550 
500 
150 
400 
350 
300 
250 
200 
150 
100 
50 




76 



TYPES OF CHIMNEY CONSTRUCTION 






















/ 


/ 


/ 


/ 


CSUUU 


Rectangular Tile Circular Tile f^omh Brick 




















1 


> 1 




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2900 




















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1 1 


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2700 


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2500 


SIZES OF CHIHflNEYS 
















1 ^ 


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/ 


/ 




/ 


/ 




Inside dimensions in inches 












1 


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2400 


36"- ,.» .." 










1 


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2300 














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2200 








1 


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24"x 44"- 








7 


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2100 


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2000^ 


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21 X 40 - 


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1900 cE 


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1800 s 

3 


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1500 o 


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1400 


24"x2S"- 20X36- //// 


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24'x 28- //// 


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1300 


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1200 




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1190 


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20"x 24- 


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900 




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300 


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6 


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y 




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lO'x 24- ,1 ' ' , / 




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700 


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600 


16"x 20l 


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500 



30 40 50 GO 70 80 90 100 

FEET iN HEIGHT BETWEEN COMBUSTION CHAMBER 

AND TOP OF CHIMNEY 



Fig. 8-7b — Probable capacities of chimneys of different forms, sizes and heights to produce 
proper draft for average cast-iron boiler of up-draft type using anthracite coal 



low horizontally to left to intersection of vertical line representing given 
height, then downward along the curve to its left end, then follow a hori- 
zontal line to left; the interior cross-sections of linings and rough brick 
above the horizontal should be ample under usual conditions. 



77 



When desiring to ascertain probable capacity of a chimney of known 
dimensions and construction, the chart is read in reverse order. 

Dotted hnes on Fig. 8-7b indicate that for 11800 lb. evaporation per 
hr. and 60-ft. chimney height, a 22-in. diameter, or 16 by 28-in. tile lining 
should be proper, or that 20 by 24-in. rough brick would be ample. 

It must, however, be borne in mind that the location of the building in 
relation to topography and surrounding structures may render a chimney 
absolutely inefficient, while another similar in every respect of height and 
cross-section, used for similar boiler and fuel, but favorably located, will be 
able to produce a superabundance of draft; also that the resistance due to 
thickness of coal bed, character and quality of fuel as well as resistance be- 
tween the combustion chamber and chimney, vary in difi^erent makes of 
boilers having similar ratings, and that these resistances form a large part 
of the total head for which chimneys are required. 

The chimney problem should be presented to the boiler manufacturer 
for his study and recommendation. 

B. Chimneys and Draft for Power Boilers* 

The height and diameter of a properly designed chimney depend upon 
the amount of fuel to be burned, the design of the flue, with its arrange- 
ment relative to the boiler or boilers, and the altitude of the plant above sea 
level. There are so many factors involved that as yet there iias been pro- 
duced no formula which is satisfactory in taking them all into consideration 
and the methods used for determining stack sizes are largely empirical. In 
this chapter a method sufficiently comprehensive and accurate to cover all 
practical cases will be developed and illustrated. 

Draft is the difference in pressure available for producing a flow of the 
gases. If the gases within a stack be heated, each cubic foot will expand, 
and the weight of the expanded gas per cubic foot will be less than that of a 
cubic foot of the cold air outside the chimney. Therefore, the unit pressure 
at the stack base due to the weight of the column of heated gas will be less 
than that due to a column of cold air. This diff'erence in pressure, like the 
difference in head of water, will cause a flow of the gases into the base of the 
stack. In its passage to the stack the cold air must pass through the furnace 
or furnaces of the boilers connected to it, and it in turn becomes heated. 
This newly heated gas also rises in the stack and the action is continuous. 
The intensity of the draft, or difference in pressure, is usually measured 
in inches of water. Assuming an atmospheric temperature of 62 deg. 
fahr. and the temperature of the gases in the chimney as 500 deg. fahr., 
and, neglecting for the moment the difference in density between the chim- 
ney gases and the air, the difference between the weights of the external air 
and the internal flue gases per cubic foot is 0.0347 lb., obtained as follows: 

Weight of a cubic foot of air at 62 deg. fahr. = 0.0761 lb. 

Weight of a cubic foot of air at 500 deg. fahr. = 0.0414 lb. 

Difference = 0.0347 lb. 



■ Reprinted from Steam by permission of Babcock & Wilcox Co. 

78 



Therefore, a chimney 100 ft. high, assumed for the purpose of iUustration 
to be suspended in the air, would have a pressure exerted on each square 
foot of its cross-sectional area at its base of 0.0347 x 100 = 3.47 lb. As 
a cubic foot of water at 62 deg. fahr. weighs 62.32 lb., an inch of water 
would exert a pressure of 62.32^12 = 5.193 lb. per sq. ft. The 100-ft. 
stack would, therefore, under the above temperature conditions, show a 
draft of 3.47-^5.193 or approximately 0.67 in. of water. 

The method best suited for determining the proper proportion of stacks 
and flues is dependent upon the principle that if the cross-sectional area 
of the stack is sufficiently large for the volume of gases to be handled, the 
intensity of the draft will depend directly upon the height; therefore, the 
method of procedure is as follows : 

(1) Select a stack of height to produce the draft required by the partic- 
ular character of fuel and amount burned per sc^uare foot of grate surface 

(2) Determine the cross-sectional area necessary to handle the gases 
without undue frictional losses. 

The application of these rules follows : 

Draft Formula: The force or intensity of the draft, not allowing for 
difference in density of air and of the flue gases, is given by the formula : 

D = 0.52 HxP(i — i) {Formula 8-1) 

in which ^ ^ ^^' 

D = draft produced, measured in inches of water, 

H = height of top of stack above grate bars in feet, 

P = atmospheric pressure in pounds per square inch, 

T = absolute atmospheric temperature, 

Ti = absolute temperature of stack gases. 

In this formula no account is taken of the density of the flue gases, it 
being assumed that it is the same as that of air. Any error arising from this 
assumption is negligible in practice, as a factor of correction is applied in 
using the formula to cover the difference between the theoretical figures and 
those corresponding to actual operating conditions. 

The force of draft at sea level (which corresponds to an atmospheric pres- 
sure of 14.7 lb. per sq. in.) produced by a chimney 100 ft. high with the 
temperature of the air at 60 deg. fahr. and that of the flue gases at 500 deg. 

fahr. is, / 1 1 \ 

D = 0.52 X 100 X 14.7 (j4j-^-1^) = 0.67 

Under the same temperature conditions this chimney at an atmospheric 
pressure of 10 lb. per sq. in. (which corresponds to an altitude of about 
10000 ft. above sea level) would produce a draft of, 

D = 0.52 X 100 X 10 (gl^-^) = 0.45 

For using this formula it is handy to tabulate values of the product, 
0.52 X 14.7 (^^_^) 

79 



which we will call K, for various values of Ti. With these values calculated 
for assumed atmospheric temperature and pressure, Formula 8-1 becomes, 

D = K H. {Formula 8-S) 

For average conditions the atmospheric pressure may be considered 
14.7 lb. per sq. in., and the temperature 60 deg. fahr. For these values 
and various stack temperatures K becomes: 

Temperature of slack gases Constant K 

750 0084 

700 0081 

650 0078 

600 0075 

550 0071 

500 0067 

450 0063 

400 0058 

350 0053 

Draft Losses : The intensity of the draft as determined by the above 
formula is theoretical and can never be observed with a draft gauge or any 
recording device. However, if the ashpit doors of the boiler are closed and 
there is no perceptible leakage of air through the boiler setting or flue, the 
draft measured at the stack base will be approximately the same as the 
theoretical draft. The difference existing at other times represents the pres- 
sure necessary to force the gases through the stack against their own inertia 
and the friction against the sides. This difference will increase with the 
velocity of the gases. With the ashpit doors closed the volume of gases 
passing to the stack is a minimum and the maximum force of draft will be 
shown by a gauge. 

As draft measurements are taken along the path of the gases, the read- 
ings grow less as the points at which they are taken are farther from the 
stack, until in the boiler ashpit, with the ashpit doors open for freely admit- 
ting the air, there is little or no perceptible rise in the water of the gauge. 
The breeching, the boiler damper, the baffles and the tubes, and the coal on 
the grates all retard the passage of the gases, and the draft from the chimney 
is required to overcome the resistance offered by the various factors. The 
draft at the rear of the boiler setting where connection is made to the stack 
or flue may be 0.5-in., while in the furnace directly over the fire it may 
not be over, say, 0.15-in., the difference being the draft required to over- 
come the resistance offered in forcing the gases through the tubes and 
around the baffling. 

One of the most important factors to be considered in designing a stack 
is the pressure required to force the air for combustion through the bed of 
fuel on the grates. This pressure will vary with the nature of the fuel 
used, and in many instances will be a large percentage of the total draft. 
In the case of natural draft, its measure is found directly by noting the 
draft in the furnace, for with properly designed ashpit doors it is evident 
that the pressure under the grates will not differ sensibly from atmospheric 
pressure. 

Loss IN Stack: The difference between the theoretical draft as de- 
termined by Formula 8-1 and the amount lost by friction in the stack 
proper, is the available draft, or that which the draft gauge indicates when 

80 



connected to the base of the stack. The sum of the losses of draft in the 
flue, boiler and furnace must be equivalent to the available draft, and as 
these quantities can be determined jProm record of experiments, the problem 
of designing a stack becomes one of proportioning it to produce a certain 
available draft. 

The loss in the stack due to friction of the gases can be calculated from 



the following formula : fW-rH 



AD = -l—r-, — {Formula 8-3) 

in which 

A D = draft loss in inches of water, 
W = weight of gas in pounds passing per second, 
C = perimeter of stack in feet, 
H = height of stack in feet, 

/ = a constant with the following values at sea level: 
.0015 for steel stacks, temperature of gases 600 deg. falir. 
.0011 for steel stacks, temperature of gases 350 deg. fahr. 
.0020 for brick or brick-lined stacks, temperature of gases 600 deg. fahr. 
.0015 for brick or brick-lined stacks, temperature of gases 350 deg. fahr. 
A = area of stack in square feet. 
This formula can also be used for calculating the frictional losses for 
flues, in which case, C = the perimeter of the flue in feet, H = the length of 
the flue in feet, the other values being the same as for stacks. 

The available draft is equal to the difference between the theoretical 
draft from Formula 8-2 and the loss from Formula 8-3, hence: 

d' = available draft = KH - ^^^^ (Formula 8-J^) 

Table 8-2 gives the available draft in inches that a stack 100 ft. high 
will produce when serving different horsepowers of boilers with the methods 
of calculation for other heights. 

Height and Diameter of Stacks: From Formula 8-4, it becomes 
evident that a stack of certain diameter, if it be increased in height, will 
produce the same available draft as one of larger diameter, the additional 
height being required to overcome the added frictional loss. It follows that 
among the various stacks that would meet the requirements of a particular 
case there must be one which can be constructed more cheaply than the 
others. It has been determined from relation of stack costs to diameters 
and heights, in connection with the formula for available draft, that the 
minimum cost stack has a diameter dependent solely upon the horsepower 
of the boilers served, and a height proportional to available draft required. 

Assuming 120 lb. of flue gas per hr. for each boiler horsepower, which 
provides for ordinary overloads and use of poor coal, the method stated gives: 

For unlined steel stack — diameter in inches = 4.68 (hp.) *. (Formula 8-5.) 
For masonry lined stack — diameter in inches = 4.92 (hp.) *. (Formula 8-6.) 

In both of these formulae, hp. = the rated horsepower of the boiler. 
From this formula the curve. Figure 8-8, has been calculated and from 
it the stack diameter for any boiler horsepower can be selected. 

81 



Table 8-2. Available Draft 

Calculated for 100-ft. stack of different diameters, assuming stack temperature of 500 deg. fahr. and 100 lb. 
of gas per hp. For other heights of stack multiply draft by height -H 100 



Horse- 


Diameter of stack in inches | 


Horse 
power 


Diameter of stack in inches 


power 


36 


42 


48 


54 


60 


66 


72 


78 


84 


90 


96 


102 


108 


114 


120 


90 


96 


102 


108 


114 


120 


132 


144 


100 
200 
300 


.64 
.55 
.41 


.62 
.55 


.61 






2600 
2700 
2800 


.47 
.45 
.44 


.53 
.52 
.50 


.56 
.55 
.55 


..59 
.58 
.58 


.61 

.60 
.60 


.62 
.62 
.61 


.64 
.64 
.64 


.65 
.65 
.65 


400 
500 
600 


.21 


.46 
.34 
.19 


.56 
.50 
.42 


.61 
.57 
.53 


.61 
.59 






















2900 
3000 
3100 


.42 
.40 
.38 


.49 
.48 
.47 


.54 
..53 
.52 


. 57 
.56 
.56 


.59 
.59 
.58 


.61 
.61 
.60 


.63 
.63 
.63 


.65 
.64 
.64 


700 
800 
900 






.34 
.23 


.48 
.43 
.36 


.56 
.52 
.49 


.60 
.58 
.56 


.63 
.61 
.60 


.63 
.62 


.64 














3200 
3300 
3400 




.45 

.44 
.42 


.51 

.50 
.49 


.55 
.54 
.53 


.58 
.57 
.56 


.60 

.59 

.59 


.63 
.62 
.62 


.64 
.64 
.64 


1000 
1100 
1200 








.29 


.45 
.40 
.35 


.53 
.50 
.47 


.58 
.56 
.54 


.61 
.60 
.58 


.63 
.62 
.61 


.64 
.63 
.63 


.64 
.64 


.65 








3500 
3600 
3700 




.40 


.48 

.47 
.45 


.52 
.52 
.51 


.56 
.55 
.55 


.58 
.58 
.57 


.62 
.61 
.61 


.64 
.63 
.63 


1300 
1100 
1500 










.29 


. 44 
.40 
.36 


..52 
.49 
.47 


..57 
.55 
.53 


.60 
.59 
.58 


.62 
.61 
.60 


.63 
.63 
.62 


.64 
.64 
.63 


.65 
.65 
.64 


.65 
.65 


.65 


3800 
3900 
4000 






.44 
.43 
.42 


.50 
.49 
.48 


.54 
.53 
.52 


.57 
.56 
.56 


.61 
.60 
.60 


.63 
.63 
.62 


1600 
1700 
1800 












.31 


.43 
.41 
.37 


.52 
.50 
.47 


.56 
.55 
.54 


.59 
.58 
.57 


.62 
.61 
.60 


.63 
.62 
.62 


.64 
.64 
.63 


.65 
.64 
.64 


.65 
.65 
.65 


4100 
4200 
4300 






.40 
.39 


. 47 
.46 
.45 


..52 
.51 
.50 


..55 
.55 

.54 


.60 
.59 
.59 


.62 
.62 
.62 


1900 
2000 
2100 














.34 


.45 
.43 
.40 


.52 
.50 
.49 


.56 

.55 

.54 


.59 
.59 
.58 


.61 
.61 
.60 


.63 
.62 
.62 


.64 
.63 
.63 


.64 
.64 
.64 


4400 
4500 
4600 








.44 
.43 
.42 


.49 
.49 
.48 


.53 

.53 

.52 


.59 
.58 
.58 


.62 
.61 
.61 


2200 
2300 
2400 
















.38 
.35 
.32 


.47 
.45 
.43 


.53 

.52 

.50 


.57 
.56 
.55 


..59 
.59 
.58 


.61 
.61 
.60 


.62 
.62 
.62 


.64 
.63 
.63 


4700 
4800 
4900 








.41 
.40 


.47 
.46 
.45 


.51 
.51 
.50 


.57 
.57 
.57 


.61 
.60 
.60 


2500 












. 41 . 49 


.54 


..57 


.60 


.61 


.63 


5000 










.44 


.49 


.56 


.60 



For other stack temperature add or deduct before multiplying by ^'^ as follows:* 



For 750 deg. fahr. 

add . 17 in. 
For 700 deg. fahr. 

add . 14 in. 



For 650 deg. fahr. 

add . 11 in. 
For 600 deg. fahr. 

add .08 in. 



For 550 deg. fahr. 

add . 04 in. 
For 450 deg. fahr. 

deduct . 04 in. 



For 400 deg. fahr. 

deduct . 09 in. 
For 350 deg. fahr. 

deduct . 14 in. 



' Results secured by this method will be approximately correct 



For stoker practice where a large stack serves a number of boilers, the 
area is usually made about one-third more than the above rules call for, 
which allows for leakage of air through the setting of any idle boilers, ir- 
regularities in operating conditions, etc. 

Stacks with diameters determined as above will give an available 
draft which bears a constant ratio of the theoretical draft, and allowing for 
the cooling of the gases in their passage upward through the stack, this 
ratio is 0.8. Using this factor in Formula 8-2, and transposing, the height of 
the chimney becomes, 

H = -^ {Formula 8-7) 



.8K 

Where H = height of stack in feet above the level of the grates, 
d^ = available draft required, 
K = constant as in Formula 8-2. 

82 



120 








































--^ 


































" 








110 




























_^ 




































, 


-'^ 
















100 
























■^'"^ 


























































90 
J 80 


















^^ 




































^ 


^ 




































^ 






























i 70 

Si 

•S 60 










^ 








































/^ 




































/ 




































1 50 
° 40 






/ 






































/ 






































/ 








































30 


/ 








































/ 








































20 

10 


/ 








































( 

















































































200 100 600 800 1000 1200 1100 IGOO 1800 2000 2200 2400 2C00 2800 3000 3200 3400 3600 3800 4000 

Horsepower of Boilers 

Fig. 8-8. Diameter of stacks and horsepower they will serve 
Computed from Formula (8-5). For brick or brick-lined stacks increase the diameter 6 per cent 

Losses in Flues : The loss of draft in straight flues due to friction and 
inertia can be calculated approximately from Formula 8-3, which was given 
for loss in stacks. It is to be borne in mind that C in this formula is the 
actual perimeter of the flue and is least, relative to the cross-sectional area, 
when the section is a circle, is greater for a square section, and greatest for a 
rectangular section. The retarding eflfect of a square flue is 12 per cent 
greater than that of a circular flue of the same area and that of a rectangular 
with sides as 1 and V/i, 15 per cent greater. The greater resistance of the 
more or less uneven brick or concrete flue is provided for in the value of the 
constants given for Formula 8-3. Both steel and brick flues should be short 
and should have as near a circular or square cross-section as possible. 
Abrupt turns are to be avoided, but as long easy sweeps require valuable 
space, it is often desirable to increase the height of the stack rather than to 
take up added space in the boiler room. Short right-angle turns reduce 
the draft by an amount which can be roughly approximated as equal to 0.05- 
in. for each turn. The turns which the gases make in leaving the damper 
box of a boiler, in entering a horizontal flue and in turning up into a stack 
should always be considered. The cross-sectional areas of the passages 
leading from the boilers to the stack should be of ample size to provide against 
undue frictional loss. It is poor economy to restrict the size of the flue and 
thus make additional stack height necessary to overcome the added friction. 
The general practice is to make flue areas the same or slightly larger than that 
of the stack ; these should be, preferably, at least 20 per cent greater, and 
a safe rule to follow in figuring flue areas is to allow 35 sq. ft. per 1000 

83 



horsepower. It is unnecessary to maintain the same size of flue the entire 
distance behind a row of boilers, and the areas at any point may be made 
proportional to the volume of gases that will pass that point. That is, the 
areas may be reduced as connections to various boilers are passed. 

With circular steel flues of approximately the same size as the stacks, or 
reduced proportionally to the volume of gases they will handle, a convenient 
rule is to allow 0.1-in. draft loss per 100 ft. of flue length and 0.05-in. for 
each right-angle turn. These figures are also good for square or rectangular 
steel flues with areas sufficient to provide against excessive frictional loss. 
For losses in brick or concrete flues, these figures should be doubled. 

Underground flues are less desirable than overhead or rear flues for the 
reason that in most instances the gases will have to make more turns where 
underground flues are used and because the cross-sectional area of such 
flues will oftentimes be decreased on account of an accumulation of dirt or 
water which it may be impossible to remove. 

In tall buildings, such as office buildings, it is frequently necessary in 
order to carry spent gases above the roofs to install a stack the height of 
which is out of all proportion to the requirements of the boilers. In such 
cases it is permissible to decrease the diameter of a stack, but care must be 
taken that this decrease is not sufficient to cause a frictional loss in the stack 
as great as the added draft intensity due to the increase in height, which 
local conditions make necessary. 

In such cases also the fact that the stack diameter is permissibly 
decreased is no reason why flue sizes connecting to the stack should be 
decreased. These should still be figured in proportion to the area of the stack 
that would be furnished under ordinary conditions or with an allowance of 
35 sq. ft. per 1000 horsepower, even though the cross-sectional area appears 
out of proportion to the stack area. 

Loss IN Boilers: In calculating the available draft of a chimney, 120 
lb. per hr. has been used as the weight of the gases per boiler horse- 
power. This covers an overload of the boiler to an extent of 50 per cent and 
provides for the use of poor coal. The loss in draft through a boiler proper 
will depend upon its type and baffling and will increase with the per cent 
of rating at which it is run. No figures can be given which will cover all 
conditions, but for approximate use in figuring the available draft necessary 
it may be assumed that the loss through a boiler will be 0.25-in. where the 
boiler is run at rating, 0.40-in. where it is run at 150 per cent of its rated 
capacity, and 0.70-in. where it is run at 200 per cent of its rated capacity. 

Loss IN Furnace: The draft loss in the furnace or through the fuel 
bed varies between wide limits. The air necessary for combustion must 
pass through the interstices of the coal on the grate. Where these are 
large, as in the case with broken coal, but little pressure is required to force 
the air tlirough the bed; but if they are small, as with bituminous slack or 
small sizes of anthracite, a much greater pressure is needed. If the draft 
is insufficient the coal will accumulate on the grates and a dead, smoky fire 
will result with the accompanying poor combustion ; if the draft is too great, 
the coal may be rapidly consumed on certain portions of the grate, leaving 

84 



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1.3 

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3 0.5 

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15 20 25 30 35 

Pounds of Coal Burned per Sq. Ft. of Grate Surface per Hour 

Fig. 8-9. Draft required at different combustion rates for various kinds of coal 

the fire thin in spots and a portion of the grates uncovered with the resulting 
losses due to an excessive amount of air. 

Draft Required for Different Fuels : For every kind of fuel and 
rate of combustion there is a certain draft with which the best general results 
are obtained. A comparatively light draft is best with the free-burning 
bituminous coals and the amount to use increases as the percentage of 
volatile matter diminishes and the fixed carbon increases, being highest for 
the small sizes of anthracites. Numerous other factors, such as the thick- 
ness of fires, the percentage of ash and the air spaces in the grates bear directly 
on this question of the draft best suited to a given combustion rate. The 
effect of these factors can only be found by experiment. It is almost im- 
possible to show by one set of curves the furnace draft required at various 
rates of combustion for all of the different conditions of fuel, etc., that may 
be met. The curves in Figure 8-9, however, give the furnace draft necessary 
to burn various kinds of coal at the combustion rates indicated by the abscis- 
sae, for a general set of conditions. These curves have been plotted from 
the records of numerous tests and allow a safe margin for economically 
burning coals of the kinds noted. 

Rate of Combustion: The amount of coal which can be burned per 
hour per square foot of grate surface is governed by the character of the coal 
and the draft available. Where the boiler and grate are properly propor- 

85 



tioned, the efficiency will be practically the same, within reasonable limits, 
for different rates of combustion. The area of the grate, and the ratio of 
this area to the boiler heating surface will depend upon the nature of the fuel 
to be burned, and the stack should be so designed as to give a draft sufficient 
to burn the maximum amount of fuel per square foot of grate surface cor- 
responding to the maximum evaporative requirements of the boiler. 

Solution of a Problem : The stack diameter can be determined from 
the curve. Figure 8-8. The height can be determined by adding the draft 
losses in the furnace, through the boiler and flues, and computing from 
Formula 8-7 the height necessary to give this draft. 

Example: Proportion a stack for boilers rated at 2000 horsepower, 
equipped with stokers, and burning bituminous coal that will evaporate 
8 lb. of water from and at 212 deg. fahr. per lb. of fuel; the ratio of boiler 
heating surface to grate surface being 50: 1; the flues being 100 ft. long and 
containing two right-angle turns; the stack to be able to handle overloads 
of 50 per cent; and the rated horsepower of the boilers based on 10 sq. ft. 
of heating surface per horsepower. 

The atmospheric temperature may be assumed as 60 deg. fahr. and 
the flue temperatures at the maximum overload as 550 deg. fahr. The 

grate surface equals 400 sq. ft. The total coal burned at rating = = — ~ — - 

= 8624 lb. The coal per square foot of grate surface per hour at rating 

400 "" "^• 

For 50 per cent overload the combustion rate will be approximately 
60 per cent greater than this, or 1.60 x 22 = 35 lb. per sq. ft. of grate 
surface per hr. The furnace draft required for the combustion rate, from 
the curve. Figure 8-9, is 0.6-in. The loss in the boiler will be 0.4-in., in the 
flue 0.1 in., and in the turns 2 x 0.05 = 0.1-in. The available draft required 
at the base of the stack is, therefore, 

Inches 

Boiler 0.4 

Furnace 0.6 

Flues 0.1 

Turns 0.1 

Total T2 

Since the available draft is 80 per cent of the theoretical draft, this draft 
due to the height required is 1.2 -^ 0.8 = 1.5 inches. 

The chimney constant for temperatures of 60 deg. fahr. and 550 deg. 
fahr. is 0.0071 and from Formula 8-7, 

H = ^=211ft. 

Its diameter from curve in Figure 8-7 is 96 in. if unhned, and 102 in. 
inside if lined with masonry. The cross-sectional area of the flue should 
be approximately 70 sq. ft. at the point where the total amount of gas is to 
be handled, tapering to the boiler farthest from the stack to a size which 
will depend upon the size of the boiler units used. 

86 



Correction in Stack Sizes for Altitudes: It has been assumed 
that a stack height for altitude will be increased inversely as the ratio of 
barometric pressure at the altitude to that at sea level, and that the stack 
diameter increases inversely as the two-fifths power of this ratio. This 
relation assumes a constant draft measured in inches of water at base of 
stack for a given rate of boiler operation, regardless of altitude. 

If the assumption be made that boilers, flues and furnaces remain the 
same, and further that the increased velocity of a given weight of air passing 
through the furnace at a higher altitude would have no effect on the com- 
bustion, the theory has been advanced* that a different law applies. 

Under the above assumptions, whenever a stack is working at its maxi- 
mum capacity at any altitude, the entire draft is utilized in overcoming the 
various resistances, each of which is proportional to the square of the velocity 
of the gases. Since boiler areas are fixed, all velocities may be related to a 
common velocity, say that within the stack, and all resistances may, there- 
fore, be expressed as proportional to the square of the chimney velocity. 
The total resistance to flow, in terms of velocity head, may be expressed in 
terms of weight of a column of external air, the numerical value of such head 
being independent of the barometric pressure. Likew ise the draft of a stack, 
expressed in height of column of external air, will be numerically independent 
of the barometric pressure. It is evident, therefore, that if a given boiler 
plant, with its stack operated with a fixed fuel, be transplanted from sea 
level to an altitude, assuming the temperatures remain constant, the total 
draft head measured in height of column of external air will be numerically 
constant. The velocity of chimney gases will, therefore, remain the same at 
altitude as at sea level and the weight of gases flowing per second with a 
fixed velocity will be proportional to the atmospheric density or inversely 
proportional to the normal barometric pressure. 

To develop a given horsepower requires a constant weight of chimney 
gas and air for combustion. Hence, as altitude is increased, the density is 
decreased and, for the assumptions given, the velocity through furnace, 
boiler passes, breeching and flues must be correspondingly greater at altitude 
than at sea level. The mean velocity, therefore, for given boiler horsepower 
and constant weight of gases will be inversely proportional to the barometric 
pressure and the velocity head measured in column of external air will be 
inversely proportional to the square of the barometric pressure. 

For stacks operating at altitude it is necessary not only to increase the 
height but also the diameter, as there is an added resistance within the stack 
due to the added friction from the additional height. This frictional loss 
can be compensated by a suitable increase in the diameter and when so com- 
pensated, the chimney height would have to be increased at a ratio inversely 
proportional to the square of the normal beirometric pressure. 

In designing a boiler for high altitudes, as already stated, the assumption 
is usually made that a given grade of fuel will require the same draft measured 
in inches of water at the boiler damper as at sea level, and this leads to mak- 
ing the stack height inversely as the barometric pressures, instead of inversely 
as the square of the barometric pressures. The correct height, no doubt, 

* Chimneys for Crude Oil, C. R. Weymouth, Trans. Am. Soc. M. E., Dec, 1912 

87 



falls somewhere between the two values as larger flues are usually used at 
the higher altitudes, whereas to obtain the ratio of the squares, the flues 
must be the same size in each case, and again the effect of an increased 
velocity of a given weight of air through the fire at a high altitude, on the 
combustion, must be neglected. In making capacity tests with coal fuel, 
no difference has been noted in the rates of combustion for a given draft 
suction measured by a water column at high and low altitudes, and this would 
make it appear that the correct height to use is more nearly that obtained 
by the inverse ratio of the barometric readings than by the inverse ratio 
of the squares of the barometric readings. If the assumption is made that 
the value falls midway between the tw o formulae, the error in using a stack 
figured in the ordinary way by making the height inversely proportional 
to the barometric readings, would differ about 10 per cent in capacity at an 
altitude of 10000 ft., which difference is well within the probable variation 
of the size determined by different methods. It would, therefore, appear 
that ample accuracy is obtained in all cases by simply making the height 
inversely proportional to the barometric readings and increasing the diameter 
so that the stacks used at high altitudes have the same frictional resistance 
as those used at low altitudes, although, if desired, the stack may be made 
somewhat higher at high altitudes than called for in order to be safe. 

The increase of stack diameter necessary to maintain the same friction 
loss is inversely as the two-fifths pow er of the barometric pressure. 

Table 8-3. Stack Capacities, Correction Factors for Altitudes 



Altitude, height 

in feet above 

sea level 



Normal 
barometer 



R, ratio barometer 

reading sea 

level to altitude 



R- 



R*^, ratio 

increase in etack 

diameter 






30.00 


1.000 


1.000 


1.000 


1000 


28.88 


1.039 


1.079 


1.015 


2000 


27.80 


1.079 


1.164 


1.030 


3000 


26.76 


1.121 


1.257 


1.047 


4000 


25.76 


1.165 


1.356 


1.063 


5000 


24.79 


1.210 


1.464 


1.079 


6000 


23.87 


1.257 


1.580 


1.096 


7000 


22.97 


1.306 


1.706 


1.113 


8000 


22.11 


1.357 


1.841 


1.130 


9000 


21.28 


1.410 


1.988 


1.147 


10000 


20.49 


1.464 


2.144 


1.165 



Table 8-3 gives the ratio of barometric readings of various altitudes 
to sea level, values for the square of this ratio and values of the two-fifths 
power of this ratio. These figures show that the altitude affects the height 
to a much greater extent than the diameter, and that practically no increase 
in diameter is necessary for altitudes up to 3000 ft. 

For high altitudes the increase in stack height necessary is, in some 
cases, such as to make the proportion of height to diameter impracticable. 
The method to be recommended in overcoming, at least partially, the great 
increase in height necessary at high altitudes is an increase in the grate sur- 
face of the boilers which the stack serves, in this way reducing the combus- 
tion rate necessary to develop a given power and hence the draft required 
for such combustion rate. 

88 



CHAPTER IX 

Boilers 

THE boiler equipment is the production center of the heating system 
and the point Avhere the bulk of the operating expense is centered. For 
this reason, a heating plant can be successful and economical only if 
the boiler equipment is of correct type, good material and workmanship, 
well proportioned from the standpoint of its work and ample in capacity. 

Service from a heating system cannot properly be termed satisfactory 
unless the desired heating effect is secured without waste of fuel and without 
excess labor at the boilers, so it is the endeavor of this chapter to promote 
a better understanding of the boiler parts and what they should do. 

Due consideration should be given to the proper selection of a boiler, 
not only as to size and capacity, but also as to its adaptability to the existing 
local conditions which, if not properly considered, may affect the success of 
the entire plant. 

It is not intended in this discussion to cover any details of boiler con- 
struction, which properly come under the province of, and can best be solved 
by, the boiler makers themselves. 

Steam boilers haA^e been built in one form or another for nearly 200 
years, yet today they are the least understood of all the important elements 
which make up a power or heating plant. 

If it were not necessary to consider the efiiciency of the performance 
of a steam boiler, such as the number of pounds of water evaporated by a 
pound of fuel, or the relation of grate surface to heating surface, etc., the 
problem would be simple. 

All the years of experience and the thousands of evaporating tests 
made have not produced any definite and reliable rule or formula for cal- 
culating either the amount of steam that will be generated per hour with a 
given fuel or the quantity of steam in pounds produced per pound of fuel 
burned in the furnace. 

Lucke* says: "There is no absolute measure of boiler performance as 
to capacity or efficiency as a basis of compeirison to measure the goodness 
of a boiler as a boiler; comparison must, therefore, be between one and 
another boiler, or one and another service condition ; one boiler may be said 
to be better than another, or one condition more favorable and another 
worse, for the result desired, but hardly more than this is possible." 

For commercial purposes, boiler capacities seem to be quite well stand- 
ardized, boilers used for heating work being rated in capacity of square 
feet of steam radiation, and boilers for power work in boiler horse-power. 

The boiler capacity rating in square feet is based on equivalent cast- 
iron direct radiation with condensation rate of 3^^ lb. steam per sq. ft. per hr. 

The American Society of Mechanical Engineers in 1885 adopted a 
double definition of the Boiler Horsepow er as follows : 

(a) The evaporation of 34.5 lb. w ater per hr. from and at 212 deg. fahr. 

* Engineering Thermodynamics 

89 



(b) The absorption by water, between fuel conditions and that of the 
steam leaving the boiler, of 33,305 B.t.u. per hr. 

A steam boiler consists of the following essential parts: A furnace in 
which the combustion of the fuel takes place; a vessel to contain water to 
be evaporated; a steam space where the steam is liberated and where the 
generated steam is contained; a heating surface to transmit the heat of the 
furnace to the water ; a smoke pipe to carry away the products of combustion, 
and various attachments, such as gauges, damper regulators, safety valves, etc. 

A proper relation of the first four parts to each other constitutes a suc- 
cessful heating boiler. 

It is of prime importance that the furnace is of proper design as regards 
grate area, size of combustion chamber, ash pit, etc., to give most efficient 
operation, permitting the consumption of the maximum effective quantity 
of fuel per square foot of grate area. Further references will be made to 
importance of selecting the proper kind of grates for the various grades of 
fuel available in various localities. 

The water space or the water-holding capacity of a boiler does not al- 
ways receive enough attention. It should be remembered that the boiler 
which holds the greatest quantity of water at or near the normal water line 
for given size or capacity is the safest one to use, because in such a boiler 
the water line is not so readily brought down to and below the danger point, 
as compared with another having only about half the water-holding capacity. 

An investigation of the various cast-iron boilers to which our remarks 
regarding the water-holding capacity particularly refer, will show that there 
is an astonishing difference in this particular feature. Selecting two boilers 
of the same capacity but of different makes, it will be found that the water- 
holding capacity at or near normal water line varies as much as 1 to 4. 
It stands to reason that the boiler from which 4 gal. of water can be with- 
drawn by lowering the water line J 2 in- will be safer than the boiler which 
shows Y2 in. lower water with loss of only 1 gallon. 

Boiler manufacturers recognize more and more that if a boiler is to be 
successful the steam space should be liberal. The velocity with which the 
steam bubbles are separated from the water in the liberating space is ex- 
tremely high. A boiler with limited steam-liberating surface will very likely 
lose its water under heavy load conditions because under the influence of 
this velocity, particles are carried over with the steam into the piping system. 

The heating surface of a boiler includes all parts of the boiler shell, 
flues, tubes, etc., covered by water and exposed to hot gases. Surface hav- 
ing steam on one side and hot gases on the other is superheating surface. 

The American Society of Mechanical Engineers recommends that in 
measuring heating surface, the side next to the gases be used. Thus when 
estimating the heating surface of water-tube boilers, the outside areas of the 
tubes are measured, and for return-tubular or fire-box boilers the inside 
areas are measured. 

The heat generated by the combustion of fuel permeates from the fur- 
nace through the heating surface to the water in the boiler. As the process 
of combustion proceeds, the heat liberated is immediately absorbed, partly 
by heat from the freshly added fuel, but mainly from the gaseous products of 



combustion. The absorption of heat by these substances causes a rise in 
their temperature and from these gases the heat is transmitted through the 
heating surfaces into the boiler water. This transmission of heat takes 
place in three distinct ways, each of which is governed by a definite law not 
applicable to the others. 

Before the heat reaches the body of the boiler water, it changes its mode 
of travel at least twice. It is first imparted to the heating surface: (a) by 
radiation from the hot fuel bed, the furnace walls and the luminous flames, 
and (b) by convection from the hot moving gaseous products of combustion. 
Upon reaching the heating surfaces the heat changes its mode of trans- 
mission and passes through the soot, metal and scale to the inner surface, 
which is in contact with the water, purely by conduction. From the wet 
side of the heating surface the heat is carried into the boiler water mainly 
by convection.* 

The water in the boiler can absorb only that heat called the "heat 
available for the boiler," which is above its own temperature. Heat below 
tliis temperature will not flow into the boiler and is, therefore, not available. 

A commercial boiler absorbs only part of the available heat, which 
expressed as a percentage, is the true boiler effciency. This efficiency de- 
pends chiefly on the arrangement of the heating surfaces. Therefore, from 
point of economy in operation, the heating surface available and its arrange- 
ment should be carefully considered by the designer when selecting boiler 
equipment for a heating plant. 

The boiler efficiency, which is the only true measure of the ability of 

the boiler to absorb heat, is expressed by the following equation : 

rr, 1 -, m • heat absorbed bv boiler 

1 rue boiler eliiciency = -, — n— pj — tt^^— j — rr- 

"^ heat available tor boner 

The efficiencies ordinarily used in commercial boiler tests may not rep- 
resent the true performance of the boiler under actual working conditions. 

Boiler capacities as given in catalogues of manufacturers of heating 
boilers are based on the elficiencies obtained in the testing laboratories, and 
these may not be representative of true conditions. In selecting a boiler 
for a heating plant, due allowance should be made to take care of this dis- 
crepancy by adding a factor of safety to compensate for the difference in 
laboratory and actual working conditions. This allowance, which may 
be called the safety factor to be added to the theoretical capacity, varies 
widely for the various types of boilers. Before determining the safety factor 
to be added to the commercial rating, the designer should carefully consider 
the type of boiler, the kind of fuel to be used, and the kind of attention the 
plant will receive, as all these bear on the performance and efficiency. 

The necessity of providing an extra safety factor is recognized also by 
the heating trade and various trade associations that have established rules 
and regulations for guidance of members in determining boiler capacities. 

The difficulty in obtaining the more desirable grades of coal has re- 
sulted in an increasing tendency to use coals which are more readily obtain- 
able and lower in cost. The grates of the boilers should therefore be 

* Bulletin 18, United States Bureau of Mines 

91 



properly designed for the fuel which will most likely be used. Different 
authorities haA^e a wide range of opinion as to the width of the air space 
that should be used between grate bar openings for a given grade of fuel. 

Professor Gebhardt recommends an air space of ^ in. between the grate 
bars and bars ^4 in. wide for power boilers and for average bituminous coal. 

For No. 3 buckwheat coal an air space of 3/16 in. and for No. 1 buck- 
wheat 5/16 in. is recommended. 

Grate areas are usually determined in proportion to the heating surface 
of the boiler, that is, for a given fuel, the grate surface and heating surface 
have a fixed ratio. For normal operation, a ratio of grate surface to heat- 
ing surface of 1 to 35 to 45 develops the rated capacity of the boiler, while 
for fine coal or overload conditions, a ratio of 1 to 25 is desirable. 

For return-tubular boilers and water-tube boilers, the following table 
shows the usual ratios of grate surface to heating surface and also the grate 
bar openings applying with these ratios when using soft coal fuel. 

Table 9-1. Grate Surfaces for Soft Coals 

^ . . ■ Ratio of erate surface to 

Coal ■ Grate bar openings heating surface. 

Mine run Slack Mine run Slack 

Va., W. Va., Md., Pa i^-in. %-m. 1:55 1:50 

Ohio, Ky.. Tenn., Ala %-% ii 1:50 1:45 

lU., Ind., Kan., Okla H - }4 H 1:45 1:40 

Col. andWyo ?^ H 1:45 1:40 

Determination of the amount of grate surface to be used under given 
conditions involves the available draft as well as the fuel to be used. The 
curves given in Figure 8-9, page 85, show hoAV much draft is necessary for 
burning different coals at various rates of combustion. 

The draft required to overcome resistances in the boiler is also given in 
Chapter 8, pages 83 and 84. These losses in the boiler and furnace must be 
deducted from the total available draft to determine the draft available for 
the fuel bed. 

The capacity of the boiler and the B.t.u. to be developed being known, 
the number of pounds of coal to be burned can be readily computed. The 
total grate area required is found by dividing the total number of pounds of 
coal to be burned by the rate of combustion taken from Figure 8-9, page 85. 

Hand-fired return tubular and water-tube boilers are readily operated 
at the rates of combustion in pounds of coal per square foot of grate area 
given in Table 9-2. 

Small boilers of the residence-heating type usually burn coal at rates 
ranging from 1 to 5 lb. per sq. ft. of grate surface per hr. and in larger heating 

Table 9-2. Rates of Combustion for Various Coals 



Anthracite 15 lb. per sq. ft. per hr. 

Semi-anthracite 16 " 

Semi-bituminous 18 " 

Eastern bituminous 20 " " 

Western bituminous 28 " 

9-2 



boilers the ratio ranges from 4 to 12 lb. per sq. ft. of grate surface per hr. 

These low rates of combustion are the result of demands for less fre- 
quent attention, in order that the man who fires the boiler may devote time 
to other work. In consequence, heating boilers are expected to do their 
work when fired once every hour or two or in residence heating, once in six 
to eight hom'S, whereas power boilers are fu-ed at regular intervals of five 
to ten minutes.* 

Another reason why heating boilers require different fu-ing methods 
to burn bituminous coals successfully is that the space in the fire-box above 
the fuel bed is usually very much smaller than is the corresponding space in 
power boilers.* This space, known as the combustion chamber, is where the 
smoky gases driven off from the coal must become mixed with air and burn. 
The more rapidly the combustible gases are driven off from the coal, the 
larger must be the space necessary for burning them completely. The 
relatively small combustion space in heating boilers makes it important 
that the firing be done in a way to prevent the gases from being driven off 
too rap idly, t 

The type of boiler to fit the given conditions most satisfactorily depends 
upon the physical conditions of the plant, as well as the type of heating 
system selected. The success of one depends upon the other. For this 
reason boiler selection is discussed also in Chapter 10, Selection of the 
Proper Type of Steam Heating System. 

On account of the great variation of governing conditions, no attempt 
will be made here to discuss in detail the method of installation of the boilers 
or their connections. 

Precautions should be taken in the design of the boiler plant to mini- 
mize bad effects from priming. 

Liberal bleeder or drip connections from the boiler header, connecting 
directly to the return header, eliminate a great percentage of this trouble. 

Priming in most cases is due to the presence of grease or oil in the boiler 
or to the presence in the water of certain alkalies which cause the water to 
foam or bubble, and be carried into the piping system by the steam. Before 
it can be expected to perform its functions uniformly, effectively and economi- 
cally, a boiler must be thoroughly cleansed of oil, scale, dirt and other im- 
purities. The priming of boilers is not confined to any particular type or 
make. The plant designer will safeguard the interest of the owner and him- 
self as well, if he makes sure that bleeder connections are made to protect 
the boiler in case of priming and that his instructions about proper cleaning 
of the boiler and the entire heating system are carried out in full by the 
heating contractor. 

For thoroughly cleaning a boiler, the safety valve should be removed 
and a sufficient quantity of soda ash should be placed within the boiler to 
cause saponification of oils and grease. A temporary overflow pipe should 
be run to waste from the safety valve outlet or highest point of the boiler. 

* Technical Paper 180, United States Bureau of Mines 

t For further reference to the importance and effect of combustion space see Technical Papers 63, 80 
and 137 of the United States Bureau of Mines 

93 



With a moderate fire and the addition of feed water as required to 
prevent injury, the foaming of the boiler will cause the flow of oil and grease 
through the overflow pipe to waste. After thorough boiling, the fire should 
be drawn and when cool, the water should be withdrawn and then the 
boiler should be thoroughly washed with clean water to remove dirt and 
chemicals. This treatment for boilers should be repeated whenever neces- 
sary as indicated by abnormal fluctuations of the water line or by the appear- 
ance of foaming. 

Damper control is an important feature of boiler operation. There are 
two classes of damper regulators, (1) those that move the damper for slight 
changes in the steam pressure, with a proportional movement due to the 
change in pressure and (2) those that operate the dampers between extreme 
positions when the steam pressure changes. The first is preferable from the 
standpoint of economical combustion. 

As mentioned in Chapter 8, the fuel in a steam-boiler furnace is made to 
burn by passing through it a current of air, which supplies the necessary 
oxygen and carries away the products of combustion. A liberal supply of 
available air is therefore very important. Yet in many cases the space 
allotted to the boiler room is inside, small and without adequate air supply 
for combustion. Boiler rooms should be of ample size and depth to ac- 
commodate the boilers without crowding, and should have an abundant 
supply of air for both combustion and ventilation. The space in front of 
the boilers should be ample for convenience and comfort. A cramped boiler 
room is not only unsightly, but it also adds to the difficulty of taking care of 
the plant efficiently. The attendant, when firing, has to stand about 4)^2 or 
5 ft. from the front of the furnace and usually about 12 to 18 in. to the 
left of a straight line running through the centre of the furnace door. He 
should have ample room to swing his scoop from the coal pile into any part 
of the furnace. 

Many a fireman is blamed for the poor economy shown by the plant he 
operates where the dissatisfaction should be charged at least partially to 
the plant designer. It is difficult to keep skillful firemen in a small, poorly- 
kept boiler room. 

The size and type of boiler to be specified and the evaporation the boiler 
will give are problems in which the advice of the boiler maker may well be 
considered. The boiler maker is usually quite willing to co-operate if 
provided with such data as the total radiation in square feet and pounds of 
condensation, total condensation of the steam and return lines in equivalent 
square feet of radiation and pounds, the quality and size of fuel available, 
the size and height of chimney and the firing period to be allowed. 



U4 



CHAPTER X 

Selection of tlie Proper Type of Steam 
Heating System 

THE heat requirements of the building having been determined, the 
next step is the selection of the proper type of steam heating system 

to fit the particular needs. It is essential that the system of supply 
and return piping shall be such that the circulation of steam will be posi- 
tively and uniformly maintained and that the air and the products of 
condensation shall be disposed of continuously in order that the system shall 
be efficient as well as economical in operation. 

Two broad types of two-pipe steam heating systems have proved so 
successful during the past 20 years that their use has become the modern 
standard practice. 

Each type is flexible in its application and may be modified in detail 
to meet the variable conditions that arise. 

These two types are the Ofen Return-Line or Modulation System and 
the Vacuum System. 

In the Open Return-Line or Modulation System a pressure slightly above 
atmosphere is maintained in the supply piping and radiators, the products 
of condensation flowing by gravity to a point of disposal at which atmos- 
pheric or occasionally slightly lower pressure exists. Here the air is vented 
through suitable devices and the condensation is either returned to the boiler, 
if one is provided, or wasted to the sewer, if the source of supply is a so-called 
"street system." 

In its simplest form a modulation system consists of a low-pressure 
steam boiler and its appurtenances, supply piping, radiating surfaces, a 
modulation or graduated control valve at the inlet of each radiator and 
a thermostatic return trap at the outlet, a system of return piping with a 
device at the end to automatically remove the air and return the water of 
condensation to the boiler. Under favorable conditions the boiler operates, 
after initial heating, for long periods under vapor or partial vacuum, but 
due to the flexibility of the system, higher pressures are permitted in severe 
weather, when maximum heating requirements exist. It is very important 
that the steam pressure shall be closely controlled by means of an extremely 
sensitive damper regulator which will maintain the pressure always within 
a few ounces of that for which the regulator is set, thus making it possible 
to operate the boiler at or near atmospheric pressure during mild weather. 
The damper regulator also serves to quickly check the fire whenever there 
is a tendency for the pressure to rise, due either to a sudden closing off of a 
considerable amount of the radiating surface or carelessness on the part of 
the attendant, after firing up the boiler. 

For reasons of safety it is necessary that the device returning the con- 
densation to the boiler shall function properly when the steam pressure 

95 



rises above the normal operating point and e^'en when, for short period, 
it reaches the blowing-off pressure of the safety ^'alve, which is ordinarily 
not over 10 lb. in an open return-line system. 

In the Vacuum System, a pressure at or slightly above or below at- 
mospheric is maintained in the supply piping and radiators, and air and the 
water resulting from condensation of steam are continuously removed by 
mechanical apparatus which maintains, in the return piping, a pressure less 
than atmospheric. The partial vacuum required to remove the air and 
condensation is produced and maintained by mechanical displacement 
of the vapors of condensation. 

The two types of systems are similar, in that a positive circulation of 
steam is secured by the natural flow of the heating medium from a higher 
to a lower pressure. The distinguishing difference between the two types 
lies in the method of removing and disposing of the air and the products of 
condensation. 

In either modulation or vacuum svstems, modidation or graduated 
supply valves, when attached to the radiators permit control of the room 
temperature by simple hand operation, ensuring a distinct saving in fuel. 
The efficiency of either systeni is dependent to a large extent upon the ability 
of the return trap on the radiator to free it of all air and water of condensation 
without at the same time perniitting the escape of any steam. 

The open-ret vu-n or modulation system finds its widest application in a 
building covering a moderate area, in which the steam requirements are for 
heating only and where the radiation can be placed high enough above the 
water line so that the condensation will flow by gravity to the boiler. The 
system is noiseless in operation, simple in design, requiring no power-driven 
apparatus and except for periodical firing of coal and removal of ashes, the 
attention required is negligible. 

There are a number of modifications of the modulation system, de- 
pending upon varying conditions, and a system installed in a residence for 
instance, may be quite different from that in a hotel or school. 

The special advantages of the vacuum system can be realized to the 
fullest extent in projects such as the following: 

(a) A group of buildings scattered over a considerable area where 
savings in cost of installation can be effected by the use of smaller size 
supply and return piping. 

(b) One or more buildings so located with respect to the boiler plant 
that lifts are necessary in the return piping. 

(c) A plant utilizing the exhaust steam from the engines for heating 
purposes, wherein the elimination of the back pressure will save directly 
in fuel cost or permit the engine to do more work with the same expenditure 
of fuel. 

The foregoing examples do not by any means cover the entire field for 
use, for the vacuum system can be used in numerous other types of build- 
ings either as a regular vacuum system or in combination with the open 
return-line system. Indeed the adaptability of the two systems to widely 
different operating conditions makes possible the choice of one or the other 
for every type of building. In the following pages certain general rules 

96 



will be given which may influence the selection of a heating system for any 
particular case. Mention will also be made of modifications which may be 
desirable or necessary to suit individual conditions. 

In determining which of these types to employ, experience is the best 
guide, as the building conditions present so many variable factors that it 
is impossible to cover the subject exhaustively within the space of this 
chapter. 

When selecting a heating system, consideration should be given to 
the following points : 

(a) Size and type of building. 

(b) Use of building. 

(c) Location of building and topography of site. 

(d) Construction and architectural features of the building. 

(e) Source of steam supply. 

(f) Operation and attendance. 

Size and Type of Building: The first point to consider is the size 
of the building and its type. 

Residences: The prospective owner of a residence is particularly 
interested in the amount of attention necessary for operation and the 
economy of fuel. Whether he attends to the heating system himself or 
employs a caretaker, he desires a plant requiring minimum attendance. 

The modulation system is the most suitable in every respect either 
for a 30-room house or for a small bungalow. Except for periodical 
feeding of coal and removal of ashes, the attention required by such a 
system is negligible. The ability to vary the boiler pressure througla a range 
from the maximum permissible in very cold weather to a pressure at or 
slightly below atmosphere in mild weather, and to control the quantity 
of heat given off from each radiator by manipulating the graduated supply 
valve, result in a distinct economy. The heat emission and the coal consump- 
tion are regulated to correspond with the outside temperature and weather 
conditions. 

Apartment Buildings: Apartment buildings are erected by the owner 
for the revenvie which they will bring and a heating plant which can be 
operated with greatest fuel saving and the least janitor service is the best 
paying proposition. Unless the building spreads over too much ground or 
the overhead return piping cannot be properly graded without too much 
complication, the modulation sj^stem is particularly adaptable. The small 
amount of attention required by this system gives the janitor of the building 
more time for other duties. Control of the amount of steam admitted into 
each radiator gives the occupant of each room or apartment a convenient 
means of temperature regulation. 

Store and Ojfice Buildings: Where no mechanical system of heating 
and ventilation need be provided and where an open-return-line system can 
be applied, the same type of heating system can be used in the small store 
building as described for residences and apartments. This also applies 
with equal force to small and medium-sized buildings for offices and other 
commercial purposes. 

07 




Fig. 10-1. The entry of a modern apartment building showing heat outlets in the side walls 



Public Bnildings: In this classification may be inchided court houses, 
post offices, hbraries, and schools of small type where the ventilating systems 
are of the indirect or direct-indirect gravity ventilation type. Such buildings 
have, as a rule, no other mechanical equipment besides the heating and 
ventilating plant. For these structures a modulation system with open- 
line return is recommended. 

9» 



We have considered so far the type of building wherein the area is 
moderate, the steam requirement is for heating purposes only, the basement 
radiation is well above the water line of the boiler and the overhead return 
piping can be properly graded, as required in the open-line system. In 
such cases the simplest form of system can be installed, requiring a minimum 
amount of attention. 

Frequently, however, conditions arise wherein the open-return piping 
cannot be run at a higher level than that of the water line of the boiler and 
discharge by gravity into the boiler, or where the radiation in the basement 
must be placed at or even below the boiler water line. The first mentioned 
situation occurs if the building covers considerable area or structural con- 
ditions cause the return piping to be kept well down from the ceiling. Where 
mechanical ventilation is installed having indirect radiation placed in the 
basement for warming the air, or where the character of the basement rooms 
is such that they will not be properly heated if the direct radiators are placed 
near the ceiling, it becomes necessary to locate them too low for successfully 
returning the water to the boilers by gravity. In such cases a vented 
receiver is installed and connected to either a motor-driven or steam-driven 
pump. The receiver contains a float at its water level, the rise and fall 
of which controls the operation of the electric motor or steam pump, and 
the water of condensation is automatically delivered to the boiler. The 
apparatus is placed at or below the floor on a suitable foundation and the 
water line of the heating system is thus governed by the level in the receiver, 
regardless of the water line of the boiler. Where no high-pressure steam is 
required for industrial or other purposes, the automatic return pump can 
be used in conjunction with low-pressure boilers, in which event the pump 
will have a motor drive. 

Where high-pressure steam is required for various purposes, one or 
more high-pressure boilers are installed. Steam for heating is reduced to 
suitable pressure by means of a pressure-reducing valve and is circulated 
through the modulation heating system by gravity, returning to the vented 
receiver. In such cases, a steam-driven return pump is installed, taking 
steam at boiler pressure and discharging the exhaust into the heating 
system through a suitable oil separator. The condensation from the various 
pieces of apparatus utilizing high-pressure steam is also delivered to the 
vented receiver and thence returned to the boiler. 

For buildings occupying considerable area and for groups of buildings 
to be heated from a common boiler plant, the vacuum system is to be 
preferred to the modulation system with vented receiver and return pump. 
Where lifts are necessary in the returns, the vacuum system is the best 
solution. In high buildings a vacuum system is usually selected, owing to 
the saving which can be effected by the reduced sizes of supply and return 
piping as well as radiator inlet valves and return traps. If high or medium- 
pressure steam is not required for any equipment or process, low-pressure 
boilers may be installed in connection with an electrically driven vacuum 
pump which will also return the condensation from the heating system to the 
boilers. From an operating standpoint a vacuum system with an electri- 
cally driven vacuum pump of the rotary type is quite as simple as the open- 

99 



return-line system or a modulation system, with a condensation pump. 
Where the steam requirements for the Ijuilding are such that high- 
pressure boilers are required, either motor-driven or steam-driven pumps 
may be used depending upon conditions which will be touched upon later. 

Use of Building: The use of the building, or the portion of time 
during which the building is in use and must be heated, is an exceedingly 
important factor in the selection of a sj^stem. 

Stores, office buildings, restaurants and the like are heated throughout 
during the daytime, while at night the requirement is only that of preventing 
the freezing of plumbing, water pipes, etc. 

In school buildings the ventilating system is usually put into operation 
about 8 o'clock in the morning and shut down at 4 o'clock in the afternoon. 
Rural schools often do not have electricity available for driving the ventil- 
ating fans and in such cases a steam engine is installed for the purpose. The 
boilers are usually operated at about SO-lb. pressure, steam for heating pur- 
poses is reduced to 1-lb. pressure and the condensation is delivered to the boil- 
ers by an automatic return-pump and receiver. The exhaust steam from the 
engine and pump are utilized in the heating system after extraction of the 
oil by passing the steam through an oil separator. 

Where electric current is available a combination modulation and 
vacuum system may be installed. In this case the boilers are operated at 
low pressure. While the mechanical ventilating system is in use, a motor- 
driven vacvuim pump is employed to remove the air and the water of con- 
densation from the heating system and discharge the water into the boilers. 
As soon as the ventilating system is shut down, the vacuum pump may be 
stopped and the direct heating system is then operated as an open-return 
line system, discharging the returns through a suitable trap, by gravity to 
the boiler. At night the heating plant recjuires almost no attention. 

The heating of a theatre may be accomplished in very much the same 
manner. In this instance however, the ventilating system is in use in the 
afternoons and evenings, during which the plant is operated as a vacuum 
system. After the close of the night performance the change is made to a 
modulation system. 

Heating systems in churches are usually operated intermittently. Where 
no mechanical ventilation is to be provided and where all radiation can 
be placed high enough above the water line for gravity return of the water 
of condensation to the boiler, a modulation system will give excellent results. 
It has the special advantage that by eliminating the use of wet returns, the 
danger of freezing of pipes, due to intermittent operation, can be avoided. 
Heating systems in churches as a rule do not receive the best of attention 
and therefore the simpler the installation, the more satisfactory the service. 
The operation of the modulation system in draining the condensation back to 
the boiler entirely by gravity also avoids the slight noise that usually accom- 
panies the action of mechanical devices, if the latter are employed for handling 
condensation. Where mechanical ventilation is installed in a church the 
combination of a modulation and vacuum system will be found to operate 
with the same reliability as described in connection with school buildings. 

100 



The use of the motor-driven vacuum pump will ensure a rapid as well as 
noiseless circulation of steam and quick remo^"al of the air during the warm- 
ing-up period. If it is not possible to eliminate the wet returns where the 
combination system is installed, care must be used to properly protect 
the pipes against freezing. 

Hotels, hospitals, institutions, asylums and the like have a 24-hour 
period during the entire heating season. It is absolutely essential that the 
service shall be continuous. Not only must the system be economical and 
noiseless in its operation, but it must also be very flexible to meet the varying 
demands of outside temperatures and weather. The comfort of each indi- 
vidual must be considered, and as is well known, the preferences vary. In 
all the above cases there are demands for high and reduced-pressure steam 
for various purposes and it is therefore probable that high-pressure boilers 
will be installed. 

With a single building covering a moderate area, an open-return-line 
system in conjunction with an automatic pump and return tank, together 
with modulation supply valves on the radiators, will meet all of the re- 
quirements outlined above. For a group of buildings or a single building 
covering considerable area, a vacuum system will be more flexible. 

In addition to all of the benefits of the modulation system, the vacuum 
pump will circulate steam very rapidly through the system, which is an 
important factor when quick heating up becomes necessary. A further 
advantage is the saving effected through the ability, in mild weather, when 
the demand for steam is light, to distribute a small volume of steam through- 
out the entire system as needed. AYith the modulation supply valve on 
each radiator properly adjusted, or with the radiators controlled auto- 
matically by thermostats, rooms on the cold side of the building will receive 
the proper amount of heat and those on the warni side will not be overheated 
and all this is brought about with a relatively small amount of steam. 

Location of Building and Topography of Site: Location of the 
building and the general topography of the site not only aft'ect the type of 
heating system used but may also influence the kind of boiler selected. 

For example, in rural districts electricity may not be available as a 
motive power or it may not be advisable on account of its unreliability. 
Where mechanical ventilation is required, as for example in a school or 
other similar building, a steam engine will be required for driving the fan. 
A type of boiler capable of generating steam at, say io to 30-lb. pressure 
must be selected. The steam for heating is reduced to 1-lb. pressure. A 
low-pressure steam pump will have to be installed to return the condensation 
to the boilers, operating in conjunction with a vented receiver and an auto- 
matic float control device. The receiver must be located a sufficient distance 
below the bottom of the indirect radiators so as to obtain the necessary 
fall required to secure a rapid flow of water by gravity. A modulation 
system of heating with open return line to receiver will give excellent results 
and if the direct radiators are provided with graduated supply valves, 
the quantity of heat given off by each may be easily controlled by hand. 

101 




JU" n n n n ; rr;-;-n-rm-n.^ '«■ 




Fig 10-2. Arrangement of cast-iron wall radiation in cove of ceiUng in a grill room. This can 

also be employed in barber shops and other basement rooms where a modulation system 

is installed' and it is necessary to keep the radiators well above the boiler water hne. 

Operation of the steam inlet valves of such radiators can, if necessary, be 

facilitated by the use of extension stems or chain attachments 




Fig. 10-3. 



Cast-iron wall radiation in garage. The radiation is placed at some distance from the floor 
level to avoid being damaged by cars and to prevent injury to tires from heat 



102 



The topography of the site may make the return of condensation 
difficult or impractical except by the use of vacuum or by direct pumping. 

Where lifts are necessary in the return the vacuum system is the only 
solution. 

A group of buildings spread out over considerable area, supplied with 
steam from a central boiler plant, may require the use of the vacuum system 
in order to balance the pressure differential between the supply and return 
at the several buildings, particularly if it is contemplated to add new build- 
ings to the group at some future time. A further distinct advantage of a 
vacuum system under these conditions lies in the ability to use smaller 
pipe sizes for both supply and return lines, with a consequent reduction in 
cost of installation. 

Construction and Architectural Features: The construction and 
architectural features of the building present a variety of problems. 

It is frequently necessary to heat finished basement rooms by placing 
the radiators under the windows or at other points near the floor. Under 
these circumstances the condensation from the low radiators will not return 
to the boilers by gravity, as they are located at or below the water line and 
it becomes necessary to install a vented receiver and an automatic return 
pump or a vacuum pump. The former will operate in conjunction with a 
modulation system, the latter with a vacuum system. 

Frequently the structural conditions of the building are such that the 
return piping has to be run near the ceiling of the basement or along the 
floor of the first story. The lifts resulting from this situation make the 
use of a vacuum system imperative. A very high building or one covering 
a very large area impose such conditions that the vacuum system is again 
the best solution of the problem. The greater pressure differential which 
results in this system, enables the use of smaller piping or with the same 
size piping reduces the back pressure which must be carried in the engines and 
pumps to secure complete circulation. 

Reference has been made to the use of modulation supply valves to 
control the quantity of steam delivered to the individual radiators. In 
department stores, loft buildings, warehouses, factories, etc., where there 
are large open spaces to be heated, usually containing a number of radiators, 
the modulation supply valves may be omitted and a fair degree of tempera- 
ture regulation may be obtained by completely shutting off one or more unit. 

Sources of Steam Supply : There are three main sources of steam supply : 

1. Live steam from high-pressure or low-pressure boilers. 

2. Exhaust steam from engines, turbines or auxiliaries. 

3. High-pressmre or low-pressure steam from outside sources. 

If steam is required for heating purposes only, the selection of the boiler 
will be a part of the heating problem, based upon the building requirements. 
Where no mechanical apparatus is necessary, low-pressure boilers will be 
the natural choice. If electric current is not available and the system 
requires fan engines, return pumps or vacuum pumps or other power-driven 
apparatus, a type of boiler should be selected which is capable of operating 

103 




Fig. 10- 1. Cast-iron wall radiation arranged under the saw tooth of a factory roof 




Fig. 10-5. Arrangement of cast-iron wall radiation on side walls of a factory building 

104 



successfully with a working steam pressure of not less than 25 to 30 lb. 

The conditions under which the heating boiler must operate are to a 
large extent the governing factor in its selection. The kind of fuel, the 
intensity of draft which can be obtained, the length of time between firing 
periods, the character of attention which the boiler will receive, the abuse 
which it will stand without injury, are all important factors which should 
receive due consideration. 

The dimensions of the fire box, the proportion of direct and indirect 
heating surface in the boiler, the area and type of grate and the available 
draft are all influenced by the kind of fuel which is to be burned. This 
in turn depends upon the geographical location of the plant and the local 
fuel market. In many cities, boilers larger than a given size are required 
to comply with more or less drastic smoke prevention laws. It will thus 
be seen that the fuel plaj-s a very important part in the choice of a boiler. 

Sufficient attention is not always paid to selecting a boiler having 
flues and surfaces perfectly accessible for cleaning. It is also important 
in operating the boiler to see that there is a systematic removal of all soot 
and dirt at regular and frequent periods. In parts of the country where 
the water contains heavy scale-forming material, boilers having interior 
pockets should be avoided as scale will accumulate easily in these pockets 
and cannot be removed even by naore frequent blowing down. 

The shape of the boiler room may have some influence upon the type 
of boiler selected. A long, narrow room may lend itself better to the use 
of tubular or steel fire-box boilers, while a nearly square space may be best 
adapted to the cast-iron sectional pattern. Where tubular boilers are selected 
provision should be made for ample space to clean the tubes and to replace 
them, when renewals become necessary. 

The question of future extensions should be considered when the problem 
is in the preliminary stage. Unless provisions are made then, the owner 
maj^ find it very expensive to add to the boiler equipment at a later date. 

In buildings requiring 24-hr. heat, such as hospitals and like institutions, 
reserve units should be installed to provide for possible breakdown. 

In low-pressure installations, where a part or all of the water is returned 
by mechanical means, such as a motor-driven return pump, or a vacuum 
pump, it frequently happens that the water is delivered intermittently 
and in "slugs" instead of continuously; or it may fail completely on account 
of interruption of the current. The boiler must be of such a type or con- 
structed of such material that it will not be injured by the sudden lowering 
of the water line, even to the dangerous point. In other words, the design 
or construction should be chosen which will permit the greatest withdrawal 
of water per inch drop in water level. 

Priming of boilers arises from a number of causes, among which may be 
mentioned grease and dirt within the boiler, impurities in the water, lack 
of proper steam disengaging surface, insufficient steam space, and too high 
velocity of steam at the boiler outlets. 

If a type of boiler likely to produce priming must be selected for 
physical reasons, the arrangement of the connecting piping must be such 
as to eliminate any possibility of trouble from this source. 

105 



The Architect must not lose sight of the fact that a boiler used solely 
for heating purposes lies idle, without a fire under it, for a period of from 
four to five months of each year, depending somewhat upon the latitude 
and length of the heating season. Recognition must be taken of this fact 
in selecting the kind of material which is best adapted to withstand the cor- 
rosive action which is likely to occur in a damp basement room. If the 
material is subject to rust and deterioration when lying idle, it should 
have additional thickness to offset this action. 

It seems hardly necessary to call attention to the fact that boilers 
should conform to all requirements of local and State ordinances, and that 
compliance with the Boiler Code of the American Society of Mechanical 
Engineers will ensure first-class material and construction. 

The designer of the plant for a residence is in most cases confronted 
with two conditions which decide the type of boiler which he shall use: 
first, smallness of the boiler room, and second, the low head room in the base- 
ment. Both suggest the use of the cast-iron type of boiler because of its 
compactness and low water line. 

If there are other uses for steam, the type of boiler or the source of 
steam supply may be definitely fixed by other considerations than the re- 
quirements of the heating system. 

Most large modern hotels in cities are provided with high-pressure 
boiler plants, either for generating their own electric power or, in case 
electric current is purchased, for operating the pumping equipment and 
furnishing steam for kitchen and laundry purposes. The vacvuim system 
with steam-operated vacuum pumps is proper for heating such buildings. 

Great progress has been made in recent years by the country towns in 
providing more convenient hotel accommodations for the traveling public. 
The owner of the small-town hotel, while not in a position to equip with 
all the refinements of a metropolitan hotel, is anxious to have his guests 
provided with comfortable and properly heated rooms and therefore wishes 
to install an efficient and economical plant. The modulation system either 
with gravity return or with vented receiver and return pump is particularly 
advantageous, giving all that can be asked in heating effect, and enabling the 
janitor or engineer, who is also, in many cases, the porter, bell boy and general 
utility man, to take care of his many other duties. 

Y. M. C. A. buildings resemble the first mentioned type of hotels in 
many respects, as in addition to the recreational features, hotel accom- 
modations are provided for the members. Restaurant and cafeteria service 
are maintained, as well as swimming pools, Turkish baths, etc., in con- 
nection with which there is a demand for high-pressure steam in addition 
to the low-pressure steam needed for heating. For this reason all the con- 
densation cannot be returned directly to the boilers. 

The heating system should be of a type which permits regulation of 
the supply of steam to the bedrooms, according to whether they are occupied 
or empty. The graduated control system of steam supply to the radiators 
by means of modulation supply valves is a logical system to adopt. A 
steam-operated pump and receiver takes care of the returns from all the 
steam-using equipment and also from the heating system. 

106 



The modern hospital has a considerable amount of steam-using equip- 
ment such as sterilizers, blanket warmers, steam cookers, dishwashing 
machines, laundry machinery, etc.. requiring steam at pressures ranging from 
30 to 90 lb. This makes a high-pressure boiler plant necessary. Many 
of the larger hospitals have their own electric power plants, and also use 
steam for operating refrigerating plants. In such cases the available exhaust 
steam should be utilized to the fullest extent and this is best accomplished 
by means of a vacuum system. 

High-pressure boilers are usually installed in manufacturing plants 
where high-pressure steam is needed for process work and cheap electric 
power is not available. In such cases the necessary electrical machinery 
for generating current is installed and the exhaust steam is used for heating. 
As with hospitals and office buildings, the vacuum system ensures quick 
circulation of steam and removal of air and reduces the back pressure to 
a minimum. Where the plant extends over considerable area, the use of 
smaller size supply and return mains, and the ability to lift the condensation 
where changes of grade occur, become important factors. 

In localities where street steam is available, with uninterrupted service 
guaranteed for the entire heating season, and where the rate does not exceed 
that at which steam can be generated in an individual plant, the installation 
of the modulation system with street steam supply provides very satis- 
factory heating for almost any type of building. 

The reduced first cost of the heating plant, due to the omission of the 
boiler and its appurtenances, and the fact that such a plant requires practi- 
cally no operating attention, make the arrangement very attractive from 
the owner's standpoint. 

The service company supplying steam to the building usually extends 
the service pipe through the fovmdation wall and to this the heating con- 
tractor makes his connection. The water of condensation is discharged to the 
sewer through a meter in the return line, except where a flat rate per square 
foot of radiation is charged, in which case no meters are used. 

This type of heating system can be installed in almost any type or size 
of building, except where too extensive area prevents satisfactory arrange- 
ment of the return line for gravity open-return circulation. In such cases, 
the motor-driven vacuum pump offers a simple means of insuring positive 
removal of the condensation and air. 

Operation and Attention: The initial cost is frequently the de- 
ciding factor in the selection of a heating system, and it is not until the 
end of the first heating season, when the purchaser finds out the cost of 
fuel and caretaker's services, that the question of operation and attention 
receives the consideration to which it is entitled. In this chapter, however, 
it is not possible to more than touch briefly upon this important subject. 

The most successful heating system is the one which will accomplish 
all of the results for which it is designed with the least amount of attention 
and the minimum expenditure for fuel. With the view of simplifying the 
system, the use of mechanical devices for handling the condensation should 
be limited to those cases where an open -line gravity return does not work 

107 



out satisfactorily. The conditions under which return pumps and vacuum 
pumps are necessary have been fully explained in previous paragraphs and 
it is not necessary to refer to the subject again. 

We cannot emphasize too strongly the important part which the radiator 
return trap plays in the economy of operation. It should be of a type that will 
permit the rapid removal of all air and all condensation but at the same time 
prevent the escape of any steam. This point is explained very thoroughly 
in Chapter 14. 

A system cannot be expected to give the best results unless all of the 
operating conditions are favorable. Three factors which have a great 
influence upon economical as well as successful operation are the location 
of the boiler room, its size and that of the chimney. 

In planning the basement of any building the architect should pay 
particular attention to both the boiler room and the coal and ash storage 
spaces. It is needless to say that the coal room should be so placed that 
the labor of stowing away the fuel, and afterwards feeding it to the boiler, 
is reduced to a minimum, and that suitable means is provided for the 
economical handling of ashes. 

Ample firing space must be provided in front of the boiler, ample room 
at the rear to give easy access to the return and blow-oft" piping and walking 
space at either side wide enough to enable the steamfitter to easily and quickly 
assemble the sections and later permit the application of the covering. 
If the boiler is the tubular type, there must be space for cleaning the tubes 
as well as for replacing them when repairs become necessary. 

Limiting the depth of the boiler room is a false economy and will only 
result in partial if not almost complete failure of the heating system to give 
satisfaction. There must be sufficient grade so that the overhead return 
piping can be given ample pitch toward the boilers, thus ensuring quick 
return of the condensation by gravity, and so that the lowest point of the 
return for an open-ret urn -line modulation system is at least 30 inches above 
the water line of the boiler. 

Lack of head room reduces the pitch of the return piping to a minimum 
and narrows the selection of boilers to perhaps a single type, having a low 
water line but otherwise not at all adapted to the work which it must perform. 
It may also compel the construction of a pit, which is not always desirable, 
or require an electric return pump which may unnecessarily complicate 
a system that would otherwise be very simple. 

Certain types of buildings require the simplest heating system possible. 
In residences the firing is infrequent and is done by the owner or a caretaker. 
The system must be rugged in design, with the least possible mechanical 
devices, but flexible enough to respond to varying changes of outside tempera- 
ture and weather. 

The janitors of school buildings have a multitude of duties to perform 
besides that of fireman. In the rural districts the school committees have 
limited appropriations for janitor service and apparatus has to be installed 
which is capable of giving satisfactory results with such unskilled attendance 
as is available. 

lOS 



As stated before, apartment houses are run on a business basis and the 
heating system must be economical of fuel and require little attention but 
must be flexible enough so that the occupants have a convenient and inde- 
pendent means of controlling the temperature of the various rooms. In 
the various types of buildings outlined above, the modulation system, 
with open return line to the boiler, will be found to meet the requirements of 
simplicity, flexibility and economy. 

Passing to the combination of the open return line with either the 
automatic retvu-n pump and vented receiver or the vacuum pump, or the 
straight vacuum system, we find the same economy and flexibihty with 
the addition of comparatively simple mechanical return apparatus. 

Summing up the advantages of the modulation and vacuum system 
we find them to be as follows: 

Modulation System.'^: 

1. Simple in design. 

2. Efficient in fuel. 

3. No expert attendance required. 

4. Quick response to demands for changes in rate of heating. 
Vacuum Sj/stems: 1. Circulation of steam is quick, positive and 

uniform. All surfaces are heated in a relatively short space of time after 
steam is turned into the system. 

2. Saving in operating cost is accomplished practically by eliminating 
back pressure upon steam engines. This either saves directly in fuel cost 
or permits the engines to do more work at same expenditure of fuel. 

3. Saving is effected through the ability during mild weather, when 
demands for heating are slight, to distribute a relatively small volume of 
steam throughout the system as needed, with a pressure at or even slightly 
below the atmosphere. In this country, mild weather constitutes about 
75 per cent of each heating season, moderately cold weather about 'iO per cent 
and only 5 per cent can be classed as "severely" cold. 

4. Saving of fviel results from utilizing the condensation and its con- 
tained heat as part of the boiler feed. 

Certain advantages are common to both systems, as follows : 
Modulation and Vacuum Systems: 1. Noiseless in operation. Water 

hammer is unheard of due to continuous relief of air and positive removal 

of condensation. 

2. Radiators maintained at 100 per cent heating efficiency due to 
complete removal of air and water. Absence of air valves on radiators 
eliminates one of the most annoying features of many heating systems. 

3. Independent temperature control of each room at the will of the 
occupant. 

4. Efficient in fuel. 

To the foregoing advantages should be added comfort and convenience. 
More and better work is obtained from occupants of properly heated 
buildings. 



109 



CHAPTER XI 

Flow of Low- Pressure Steam Through Piping 

FLOW OF Steam Through Pipes: Flow of steam through piping is 
caused by difference in pressure, which diminishes continually from 

the source to the outlet, due to frictional resistance, deflection, con- 
traction and expansion. Likewise there is a continual drop in temperature 
due to the transmission of heat through the walls of the piping. 

Steam at initial pressure and density, but without material velocity, as 
in a boiler, requires a certain pressure drop, to impart initial velocity in the 
main. This drop varies with the velocity required, density of steam and 
shape of the orifice at entrance of the main. The pressure drop or head 
required for a given velocity, as of initial density at a point about three 
diameters beyond the entrance of a steam main, with sharp entrance edge, 
has been found from tests of the weight of low-pressure steam passing 
through a cylindrical sharp-edged orifice of length equal to three diameters. 
The pressure difference or head (hi) necessary to produce such velocity (vi) 
is fully 1.7 times that found by the well known velocity formula, v = V2 gh. 

It seems reasonable to assume that a like pressure drop is necessary to 
impart initial velocity within the heating main from a boiler or steam drum, 
as contrasted with the exhaust of an engine, reducing valve, etc. 

Table 11-1 gives 1.7 times the pressure drop or head (hi) in pounds 
and ounces per square inch, based on the above assumption. 



Table 11-1. Velocity of Steam in Feet per Minute Within Entrance of Main 
Initial Density) Produced by Pressure Drop (pi — P;)^h 
From various absolute initial pressures in pounds per sq. inch=pi 



(as of 



Pi-Pe 

Ounces 

per sq. 

inch 



Pi-P= 
Pounds 
per sq. 

inch 



Velocity in feet per minute 



Absolute initial pressure pi 
17 18 



19 





.01 


2260 


2203 


2138 


2086 


2036 


1980 


H 


.0156 


2830 


2758 


2665 


2610 


2544 


2475 




.02 


3200 


3115 


3020 


2950 


2880 


2800 


Vi 


.0312 


3995 


3885 


3770 


3680 


3595 


3495 




.04 


4530 


4405 


4270 


4175 


4070 


3960 


H 


.0468 


4910 


4775 


4625 


4520 


4420 


4280 




.05 


5060 


4930 


4780 


4660 


4540 


4420 


1 


.0625 


5660 


5520 


5340 


5220 


5090 


4950 




.07 


6000 


5840 


5660 


5520 


5390 


5240 


Ik' 


.0781 


6350 


6180 


5980 


5840 


5710 


5540 




.08 


6420 


6240 


6050 


5910 


5770 


5610 




.09 


6800 


6615 


6410 


6260 


6120 


5940 


Wi 


.0937 


6940 


6750 


6540 


6390 


6250 


6060 




.1 


7170 


6980 


6760 


6610 


6460 


6260 




.11 


7520 


7320 


7090 


6925 


6770 


6570 




.12 


7860 


7650 


7420 


7240 


7060 


6870 


•-> 


.125 


8020 


7810 


7560 


7390 


7220 


7010 




.13 


8180 


7960 


7710 


7520 


7350 


7150 




.14 


8470 


8250 


7990 


7800 


7610 


7410 




.15 


8790 


8560 


8290 


8090 


7910 


7680 


2M 


.1562 


8970 


8740 


8460 


8760 


8080 


7840 



110 



Friction in Run: Steam, having attained initial velocity at the entrance 
of the main by a pressure drop (p, — ps), will require a further drop (p2 — ps) 
to overcome friction. 

Various formulae have been published by which to determine the 
velocity or weight of steam of given quality which with a given pressure 
drop will flow in a given time through a given length of straight pipe of 
given uniform diameter. 

Analysis of the principal formulae, after reduction to common terms, 
indicates a substantial agreement among the majority of these formulae 
n the following fundamentals : 

that the velocity varies as the square root of the pressure drop. 

that the velocitv varies as -j r— 

density 

that the pressure drop varies as 



density 

that the pressure drop is proportional to length of run. 
that the pressure drop varies as the square of the weight flowing. 
The various fundamental equations for frictionless pipes may be 
reduced to the following form : 



w = 



(P2 - Ps) - d" 



V- 



and the allowance made for friction by multiplying the radical by a constant 
or numerical value, dependent on the diameter, in the following form: 



w = c 



(P2 - ps) - d' 



s 



V xL or (L + y) 
in which 

w = weight of steam flowing per minute. 

c = a constant or numerical value 

Pi = absolute pressure of initial steam when quiescent. 

P2 = absolute pressure within entrance of main. 

Ps = absolute pressure near end of main. 

d = diameter in inches. 

L = length of run in feet. 

X = a factor of L derived from some sub-formula. 

y = a formula or sum to be added to L in the basic equation. 

= mean weight of 1 cu. ft. of steam in pounds.. 

Regarding the value of c, the late Professor Kent made the following 
apt statement: 

"The coefficient of friction according to different authorities varies 
according to laws about which they do not agree." 

Investigation demonstrates that many of the laboratory experiments 
and tests of commercial pipe lines upon which the values of c, x and y have 

111 



been estimated were so made as to include the pressure drop necessary for 
initial velocity while in others this is not included. Other tests appear 
to have been made on but one or at best a very few different sizes of pipe 
and lengths of run. 

Some authorities assume that the factor c (which includes all friction) 
is constant for all sizes of pipe irrespective of relation of perimeter to in- 
cluded area of cross section; in this respect differing materially from all the 
conmionly accepted formulae for flow of water. These among themselves 
assign materially different constant values to c. 

Other authorities assign values varying with diameter, thereby recog- 
nizing the proportionate relation of perimeter to cross-section and the in- 
fluence of surface retardation on the flowing mass. The two principal 
investigators of the latter school do not dift'er materially in the values assigned 
to c although J. M. Spitzglass, in his analysis,* goes exhaustively into 
the frictional elements (skin friction due to rubbing of the fluid on the rough 
surface of pipe and internal friction due to relative motion of particles of 
fluid on each other) and deduces a formula which takes into consideration 
both the coefficient of friction and the relative capacity of pipes of various 
diameters together with experimental coefficients for the various fluids. 

Gebhart in his analysis of this subject makes the following very practical 
statement : 

"Notwithstanding the numerous investigations conducted on labora- 
tory apparatus and on pipe lines under actual power plant conditions, there 
is no trustworthy rule for accurately determining the flow of steam in 
commercial piping." 

Professor R. C. Carpenter in his investigations regarding flow of steam 
in pipes reaches the following conclusion: 

"For practical conditions, it is rather better to have aii allowance 
in pipes for an excess in friction than to have the reverse condition true." 

From an extended experience in steam heating practice and installation, 
it seems a fair conclusion that in none of the published formulae is sufficient 
consideration given to the excess friction liable to be encountered due to 
reduction in area and frictional resistance due to the very usual neglect of 
the workmen to ream pipes true after cutting. 

This excess friction is likely to increase as the proportion of perim- 
eter to area increases and be a serious source of inaccuracy in the deter- 
mination of flow in the smaller sizes of commercial piping, and pipes if 
inadequate, when once installed, will usually remain a source of trouble 
and discredit. 

This has led to the use of a table in which the value of c in the formula 



' ^ has been increased for the smaller sizes bevond 

\ L 

that of any of the authorities above referred to. 

These values of c and the flow table based thereon are oft'ered as those 



* Flou' of Fluids and Frictional Resistance in Pipes, J. M. Spitzglass, Armour Engineer. March and 
May, 1917 

112 



found to be adequate in practice under any but the worst practical con- 
ditions to which it has been apphed. 

W = 60c 

V 

W = weight of steam in pounds per hour 

Diameter of pipe ,,/ ^i,, -.^,, .-,„ 

in inches * 2 - 

Value of c 31 11 41 49 

Diameter of pipe o" q" in" 

in inches 
Value of c 61.2 64.8 65.4 

This formula makes no allowance for drop due to initial velocity, 

condensation, or changes in direction or area of pipe. 

Table 11-2, Pages 114-5, has been computed from Formula 11-1 

For example, ascertain the pressure necessary to overcome friction 

in a 400-ft. run of 4-in. straight pipe when conveying 600 lb. of steam per 

hr. and p2 is 16 lb. per sq. in. absolute. 

(~y = (0.821)' = 0.674 lb. pressure drop for 1000 ft. due to weight of 

steam other than tabulated; therefore, pressure drop for given length, or 
400 feet is: 



(P2 - Ps) g-d' 




{Formula 11-1 


L 




per hour. 






21" 3" 3i" 


4" 


5" 6" 7" 


52 55.6 57 


59 


61 62.5 63.4 


12" 14" 


16" 


18" 20" 


66 65 


65 


65 65 



(400\ 
Yqqq) = 0.270 lb. per sq. inch. 



Condensation Loss: Tlirough the entire length of run, there is a further 
loss of pressure, due to radiation and condensation. This loss is least in 
well covered mains with still air, at high temperature. Condensation in 
long runs of small pipe frequently causes the greatest loss of weight and oc- 
casions large pressure drop. 

Figure 11-1, Page 116, gives averages of condensation loss in bare and 
covered pipes for various differences between temperature of steam in pipe 
and air surrounding the pipe or its covering. 

The following example is given to call attention to what is likely to 
happen if tabular steam values, for straight runs, be used to size mains sup- 
plying radiation through long runs of small pipe, even if the mauns are well 
insulated. From Table 11-2 it will be seen that a 13/2-in. pipe with a friction 
loss of 1/10 pound per 100 ft. and an initial pressure of 16 lb. absolute will 
convey steam at an hom-ly rate of 55.1 lb. or 53250 B.t.u. per hour. 

By inspection of Figure 11-1, we find that if the difference in tempera- 
ture between steam in the pipe and air surrounding it is 150 deg. fahr. 
and the pipe has good insulation, there is transmitted through that cover- 
ing about 25 B.t.u. per lin. ft. (J^ sq. ft.), or 25000 B.t.u. per hour for 1000 
ft. run. Therefore, about 60 per cent of the entering steam will be con- 
densed. 

Effect of Deflection, Contraction and Expansion: Mains are seldom 
straight cylindrical pipe from end to end. Normally there are elbows, 
valves, branch outlets, reductions in size, separators, expansion joints, etc., 

113 



each adding to frictional resistance and causing pressure drop. 

Although not technically accurate, it has been found convenient in 
estimating, to express these resistances in units of the additional length of 
run of straight pipe that would produce an equal effect. Table 11-3, which 
is believed to be conservative and likely to produce results well within the 
tolerance necessary in so complicated a subject, is figured upon this basis. 

Fittings of different manufacturers vary in resistance in similar sizes 
and similar fittings vary in percentage of resistance. No Yery careful 
tests covering the entire range of flow of water, air and steam are available 
for data, but those that do exist have been studied in making up this table. 

Pressure Drop: The necessity for pressure drop to create flow in 
heating systems is further explained in following pages. Modulation and 
vacuum systems differ in degree of this pressure drop rather than in principle. 

Table 11-2. Weight of Steam Flowing Uniformly in One Hour Through Standard 

Straight Level Pipes 1000 ft. Long, with a Loss of 1 lb. per Sq. In., 

from Given Initial Pressure Within Inlet End 

P2 = absolute initial pressure within entrance of main. r = latent heat of steam at absolute initial 
pressure P2. 1000 B.t.u. = thousands of B.t.u. contained in the entering steam. V = velocity 
of steam in feet per min. at initial density 





5 *> 

.s.s 

•35 

3 . 

■5,2 


.Is 

I.S 

3 . 

1.315 


S 

«.. 3 

°-5 

in 

as..s 


^.9 

'it 

3 « 


Qj "= a) 

.ass 

2.9 
2.3 


Sq. ft. of 
ext. surface 
per linear ft. 


1 
2 .S 


11 

Ss 

34 
41 

4.4 

49 

52 

55.6 

57 

59 


P-> 


15 


16 


17 


18 


19 


20 




s 


26.27 


24.79 


23.38 


22.16 


21.07 


20.08 


1 

Is 


1 
s 


.03806 


.04042 


.04277 


.04512 


.04746 


.04980 


K'S 


r 


969.7 


967.6 


965.6 


963.7 


961.8 


960 


1" 


1.019 


167.5 


.86 


.345 


1.13 


Lb. 

1000 B.t.u. 

Vel. ft.-min. 


14.2 
13.7 

1044 

33,9 
32.8 
1428 
53.4 
51.7 
1650 
111,2 
107.9 
2082 

184.1 
178 

2432 


14.63 

14.15 

1001 

34.92 

33.75 

1385 


15.08 
14.5 

983 
35.92 
34.7 
1344 


15.48 
14.9 

955 

36.90 

35.5 

1310 

58.2 

56 

1518 

121 

116.4 

1906 

201 . 5 

194 

2240 

369.5 

356 
2660 

545 

524 
2925 

774 

745 
3235 
1405 
1350 
3740 
2280 
2190 
4195 
3340 
3210 
4580 


15,88 

15,27 
934 
37.86 
36.4 
1276 
59.65 
57.3 

1478 

124.2 

119.5 

1865 

205 

197 

2170 

378 

363 

2595 

558 

537 

2860 

794 

763 

3155 


16.23 

15.6 
908 


H" 


1.38 


1.66 


96.1 


1.5 


. 431 


2,235 


Lb. 

1000 B.t.u. 

v 


38.80 
37.3 
1248 


IJ" 


1.61 


1.9 


70.6 


2.04 


2.01 
1.61 
1.33 
1.09 
.955 
.849 
.686 
.577 
.501 


.497 


3.28 


Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

v 


55.1 
53.25 

1607 
114.5 
110.8 

2022 
189.2 
182.9 

2353 

349 
337.5 

2808 
515 
498 

3095 


56.6 

54.6 

1554 

117.7 

113.5 

1960 

195.2 

188.3 

2295 

3.59 

347 

2725 

530 

512 

3010 

752 

725 

3315 

1368 

1322 

3835 

2218 

2140 

4300 

3250 

3140 

4710 


61,1 
58.7 
1444 


2" 


2.067 


2.375 


42.9 
30.15 


3.36 


.621 


6.13 


127 

122 

1820 


9i" 

-2 


2.469 


2.875 


4.78 


.751 
.991 


9.58 
16.47 


211 

202.5 

2130 


3" 


3.068 


3.5 


19.5 


7.39 


Lb. 

1000 B.t.u. 

v 


339 

328.5 
2890 

500 

485 
3190 


387 

372 

2530 


31" 


3.548 


4 


14.58 
li.3 


9.89 


1.046 


23.7 


Lb. 

1000 B.t.u. 

v 

Lb. 

1000 B.t.u. 

v 

Lb. 

1000 B.t.u. 

v 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

v 


572 

549 

2790 


4" 


4.026 


4.5 


12.73 


1.177 


32.53 


710 

688 

3520 


731 

706 

3415 


812 

779 

3075 


5" 


5.047 


5.563 


7. 22 


19.99 


1.457 


57.17 
90.6 


61 

62,5 

63.4 


1290 
1250 
4070 
2092 
2025 
4565 
3065 
2970 
5000 


1328 
1284 
3950 
2158 
2085 
4440 
3155 
3050 
4845 


1440 
1385 
3640 


1475 
1420 
3550 


6" 


6.065 


6.625 


4.99 


28.89 
38.74 


1.733 


2340 
2250 
4100 


2392 
2295 
3980 


7" 


7.023 


7.625 


3.72 


2, 


130.7 


3425 
3290 
4475 


3506 
3365 
4360 



114 



Table 11-2 — Continued 





1" 

'is 

ti 


'O VI 
M.S 


4) 

a 


•S.5 

Is 


S 

S 
*0 3 

■ *.: "^ 

■So,!-; 

.443 
.397 
. 355 
.299 
.255 
.239 
.212 
.191 


Sq. ft. of 
ex. surface 
per linear ft- 


o 
3 .S 


11 

ds 

64.2 
64.8 
65.4 


P- 


IS 


16 


17 


18 


19 


20 




s 


26.27 


24.79 


23 38 


22.16 


21.07 


20 08 


"3 


1 
s 


03806 


.04042 


.04277 


.04512 


.04746 


.04980 


&;■« 


r 


969.7 


967 6 


965.6 


963.7 


961.8 


960 


8" 


7.981 


8.625 


2.88 


50.02 


2.257 


180 


Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 

Lb. 

1000 B.t.u. 

V 


4275 

4140 

5380 

5735 

5560 

5760 

7680 

7440 

6150 

12170 

11750 

6800 

18420 

17850 

7290 

22750 

22050 

7630 

30850 

29940 

8100 

40300 

39200 

8.550 


4400 
4260 

5240 


4530 

4375 
5080 


4652 

4480 

4950 

6210 

6005 

5290 

8360 

8040 

5640 

13270 

127.50 

6230 

20080 

19300 

6700 

24800 

23900 

7020 


4775 

4580 

4830 

6400 

6150 

5175 

8600 

8270 

5530 

13620 

13100 

6100 

20580 

19780 

6.540 


4485 
4690 
4720 


9" 


8.911 


9.625 


2. 29 


62.72 


2.58 


239 


5900 

5710 

5600 

7930 

7660 

5880 

12.530 

12120 

6600 

18970 

18340 

7060 

23410 

22620 

7410 

317.50 

30700 

7850 

41600 

40200 

8310 


6075 
5860 
5440 


6560 
6310 
5050 


10" 


10.02 


10.75 


1.83 


78.82 


2.82 


317.7 


8145 

7870 

5790 
12900 
12460 

6410 
19520 
18820 

6800 
24100 
23250 

7190 
32700 
31650 

7650 
42800 
41300 

8050 


8800 
8450 
5380 


12" 


12 


12,75 
15 


1.27 


113.1 


3.3 


198. 8 


66 
65 


13940 

13360 

5940 


14" 


14.25 


.901 


159.5 


3.90 


766.5 


21100 

20250 

6400 


16" 


15.5 


16 


.765 


188.3 


4 16 


945.9 


65 


25150 
21150 

6810 
31150 
33150 

7270 
45200 
43400 

7660 


26100 

25100 

6660 


18" 


17.5 


18 


.601 


240 


4.71 


1281 


65 
65 


33550 
32300 

7425 
44000 
42300 

7850 


352.50 

33850 

7060 


20" 


19.5 


20 


.483 


298 


5.23 


1679 


Lb. 

1000 B.t.u. 

V 


46250 
44400 

7475 



The pressure drop for lengths other than 1000 ft. will be 



1000 



X the tabular pressure drop, 
/lOOO 



where Li is the new length in feet, and the weight of steam discharged will be / lOOO X the discharge 
given above. \ Li 

The pressure drop varies as -j r- — The pressure drop varies as the (weight) 2. 

The weight of steam flowing varies as v pressure drop. 



Table 11-3. Resistance of Fittings in Feet of Straight Pipe to be Added to 

Actual Length of Run 







Long sweep 


Medium 


Standard 










Size of pipe 




ell 


sweep ell 


ell 


Angle 


Short 


Side 
outlet 


Globe 


in inches 




standard 
tee 


run of 
tee 


reduced 
tee 


valve 


bend 


tee 


valve 




Length in feet to be added in run 


2 


*-> 


3 


4 


5 


9 


11 


17 


19 


2J^ 


3 


4 


5 


7 


12 


15 


21 


26 


3 


3 


5 


6 


10 


16 


19 


27 


33 


SV2 


4 


6 


8 


12 


19 


22 


32 


39 . 


4 


5 


7 


9 


14 


22 


24 


36 


45 


5 


7 


9 


11 


18 


27 


30 


44 


58 


6 


9 


11 


14 


22 


32 


36 


51 


70 


7 


10 


13 


17 


26 


37 


41 


56 


82 


8 


12 


15 


20 


31 


42 


47 


63 


94 


9 


13 


17 


22 


35 


47 


52 


68 


104 


10 


15 


20 


24 


39 


52 


57 


76 


117 


12 


18 


24 


30 


47 


62 


68 


91 


140 


14 


20 


26 


33 


53 


71 


79 


105 


160 



115 



:300 



• 280 



<260 



= 240 



!220 



bo 

.5 200 
-a 



:180 



1160 



1140 



■120 



iioo 



80 



60 



^. 40 



20 



10 



bJ3 
Q 



























/ 






















































/ 


































\ 


















/ 


1 




























/ 






























/ 




























/ 


/ 




























/ 


/ 


























/ 


/ 






























/ 


























/ 


/ 
































/ 
























/ 


























































/ 




































1 






















/ 


























































/ 


























































/ 






































/ 




















/ 








































/ 


















/ 








































v^ 


1 
















/ 








































ri/ 
















/ 










































.^ 


/ 














/ 










































< 


4/ 














. / 


/ 










































!■/ 












■^ 


7 












































7 












,^ 


V 














































/ 










2 


f 




































t 








f 


1 








,1 


















































1 










y 


{ 
















' 
































1 










/ 
















































} 










/ 


















































/ 








/ 














































\ 


1 


1 








/ 


























































/ 










































^ 










1 






A 








































^ 


^ 


















A 


































^ 
























/ 




























t 


\^- 


^ 


■-^ 


















A 




























,^^ 


vv^ 




























/ 






















^"0-, 


-• * 






























/ 


















^ 




^ 


^ 


c<^^ 
































A 


t 














'i 


'''l 




































/ 




/ 














^ 










































/ 


/ 














-^ 












































/ 


/ 








^ 


^ 














































/ 


/ 








/ 


















































// 


/ 




^ 




















































^ 


^ 

























































240 260 280 300 



10 20 30 40 50 60 70 80 90100 120 140 160 ISO 200 220 
B.t.u. Radiation per Hour per Sq. Ft. of Pipe 

Fig. 11-1. Heat transmission in B.t.u. per hour per square feet of bare and covered pipe 

Pressure Drop in Modulation Systems: The typical modulation system, 
as illustrated in Figure 11-2, when operating at normal rate, requires suffi- 
cient pressure against the valve piece of the vent valve pi to cause it to 
open against the atmospheric pressure. Representing atmospheric pressure 
as p and this excess pressure as pi the expressions p + pi = pressure at en- 
trance of vent valve. 

116 



^aFTT^. 



SleamMain, Vent Valves 




1^:^ y ^^/^ ^CU 



Return 
Header__ 



Boiler 



^^ 





-Steam Riser 
Jeturn Riser 

BETURN TRAP 



:> 



7 






■?i^\ 



Supp'y Vjlve 



Dry Return 



Waler Line ot Boiler 



jas 



Cold Water Connection 



Wet Return., 



H2 




j£ 



-/ M -Tn Drain ■Cliecl< Valve 



Fig. 11-2. Diagram of modulation system layout to illustrate pressure drop 

To cause the air to flow from the vent trap through the vent valve 
orifice requires a pressure difi'erence, which may be represented by ps, vary- 
ing with velocity of flow. Therefore, pressure in the vent trap becomes 
= p + pi + P2. To cause the air to flow from outlet of the radiator trap 
through return main to the vent trap, there must be another pressure 
difference, represented by ps, dependent on velocity of flow; also another 
pressure difference through orifice of radiator trap p4. Therefore, pressure 
ps in the radiator at the time of air displacement by steam from the boiler 
must equal the sum ofp4 + p3 + p2 + pi + p. Of these last expressions 
p is relatively constant with gauge at zero lb. The flow through the vent valve 
pi is nearly constant, being mainly that pressure difference necessary to 
overcome the gravity of the valve piece, and adhesion of wet surfaces of the 
seat. The variable due to the volume of air passing is so slight, owing to 
low velocity, that it may usually be neglected. 

The pressure pi of vent valve suitable for a modulation system is 
lb. per sq. in. 

The pressure drop through vent valve orifice p2 is a variable, greatest 
during initial heating-up period when a large volume of cool air is expelled 
from the heating system, and least during normal heating when velocity 
is that slight amount due to entrained air in condensation passing from the 
radiation. Air-vent traps are rated on basis of flow of initial air in 40 min- 
utes in a system with ^V ^- P^r sq. in. differential pressure through the 
vent-trap valve. 

For less than rated capacity, either the time or pressure factor or both 
may be less; for instance, with p, constant, one-half the amount of radiation 
would require one-half the time period. 

117 



1 



The pressure drop in the return main pa is also a variable, greatest 
during initial heating and dependent on length of run and maximum 
velocity. In a well-proportioned system, ps should never exceed 1/20 lb. 
per sq. in. differential between the farthest radiator trap and the vent trap, 
and during normal heating it is so slight as to be almost negligible. 

The pressure drop through a radiator trap p4 is also a variable, least 
and almost negligible during initial expulsion of air from radiation, at which 
time the trap-valve orifice is wide open. As the radiator warms up and con- 
densation flows through the trap orifice with the last of the contained air, 
P4 gradually becomes greater. It becomes maximum when condensation at 
or near steam temperature is flowing at the full rating of the return trap 
for a given pi of }/$ lb. per sq. in., which pressure has been selected from 
tabular ratings of return traps (page 238). It is good practice not to have 
P4 exceed }/s lb. per sq. in. where it is advisable to carry less than 3^ lb. 
pressure on the boiler and }^ lb. where a pressure of 1 or 2 lb. can be ceirried. 

Representing the pressure difference necessary for flow, initially of air 
and subsequently of steam, from the radiator branch through the inlet or 
modulation valve to the radiator, requires another variable pe, H lb- P^r 
sq. in. at full rating, least (in a properly designed modulation valve full 
open), during initial expulsion of air, and greatest when the valve is partly 
closed for modulation effect, at the selected rating of this valve, for a given 
pressure difference pe. 

p? is usually assumed for a system of mains, risers, branches and run- 
outs, designed from data on flow of steam in mains given in Table 11-8 
to carry the maximuni normal quantity of steam in a given time from the 
main heat pipe near the boiler to the inlet valve of farthest radiator, with 
this pressure drop p?. 

The quantity of steam, referred to in the preceding paragraph, flowing 
tlirough the selected size main supply pipe will have velocity at the boiler 
which depends upon the pipe area and the volume of steam flowing in unit 
of time. To impart this velocity to the steam from a state of quies- 
cence in the steam space of the boiler and to offset the resistance of the 
orifice requires another pressure drop ps- Knowing the maximum normal 
quantity of steam and the size of the main, the pressure drop to give the 
resulting velocity can be obtained from Table 11-1. 

It follows from consideration of the above that the pressure in the boiler 
Pb at time of maximum normal heating effect must be the sum of p + Pi + P2 
etc., including ps as follows: 

p, constant at atmospheric pressure. 

pi, at least intermittent at that time. • 

P2, negligible at that time. 

Ps, negligible at that time if return has proper grade. 

P4, tabulair if fuU rated value in radiation is on farthest unit. 

Po, pressure drop in radiator, negligible at that time. 

pe, tabular if fuU rated value in radiation is on farthest unit. 

Pt, from assumption in design from flow of steam in main. (Table 11-8). 

Ps, that required for velocity head under above assumption. (Table 11-1). 

U8 



The heating-up period will vary in accordance with initial pressure in 
the source of steam supply. Usually some time is required to raise steam to 
the normal pressure Pb- During that time air will be expelled and steam 
flow into the radiation at different rates due to the varying pressure caused by 
the increasing resistance of pi + ps- If steam is constantly supplied during 
the heating-up period at pressure Pb, as when a central plant is the steam 
source, the condensation rate in the radiation due to absorption of heat 
by the metal will be as far in excess of normal as the sum of maximum 
Pi + P2 + Ps + an intermediate p4, deducted from Pb — p, will produce 
a pressure difference (pd) to cause initial velocity. It will flow through 
mains at a rate substantially in the same proportion as pd is to py, provided 
initial velocity equal to ps has been previously imparted to the steam within 
the entrance of the main. 

The intermediate p4 referred to in the above paragraph is caused by 
the partial extension of the thermostatically moved valve piece in the return 
trap. This factor varies from full open and minimum resistance, when 
steam is first admitted and chilled condensation commences to pass, to 
nearly closed position and full resistance, when the radiator is completely 
filled up to the return trap with steam at a temperature corresponding 
with its pressure. 

Modulation systems when operated at less than normal condensation 
may circulate continuously at pressure materially lower than the normal 
Pb, or may be intermittently operated at a pressure less than p, provided the 
air has first been expelled by a higher operating pressure. Under such 
conditions, however, the system will gradually become air-bound and cease 
to circulate. 

In designing modulation systems, all. gravity drip points should be pro- 
vided with a hydraulic head (Hi) of at least 23^^ feet for each pound per 
square inch of p? + ps + frictional resistance in run of gravity drip and re- 
sistance of check valve between gravity drip and boiler, when the boiler is 
generating steam at its full capacity to supply cold radiation. 

If the gravity drip be taken from radiation located below the dry re- 
turn, with thermostatic air vent up to the dry return, then the resistance of 
any additional branch main, radiator, valve and check valve on gravity drip, 
must be added to p? + pe, etc., given above, to determine whether H2 is 
sufficient. 

The hydraulic head in inches of water on the check valves will vary 
with the make, weight and angle of the clapper and the size of pipe tapping. 
This head is seldom less than 3 in. with the clapper at an angle of 10 
deg. from vertical and may run up to 18 in. and higher with vertical-lift 
valve pieces. 

In installing radiation with gravity drip for condensation as above, it is 
important that the branch connections and valve to such radiation have 
sufficient free area when in use, to cause little or no reduction in pressure in 
the radiator, from that in the main. A partially closed inlet valve might 
cause such a reduction in pressure, when added to the other resistances, that 
there would not remain sufficient total pressure in the radiator, when added 
to the available H2, to overcome the pressure Pb plus the check valve resist- 

119 



ance in gravity drip. In consequence of this, condensation would build up 
in the column H2, seal the radiator outlet and finally cause the radiator to 
become water-logged, possibly draining at a partial condensation rate, 
through the air vent into the dry return line. 

The closing level of the air-vent trap should be located at such a height 
above the water line of the boiler that a hydraulic column is produced fully 
equal to the resistance of its check valve and drain pipe plus normal Pf 

This, however, is not as important as to have Hi and Ho ample. An 
air pressure wdll accumulate in this vent trap due to closing of the vent out- 
let, when column H is not sufficient to overcome resistance of drip line and 
the pressure Pb in the boiler. This air pressure will continue to build up 
with vent closed, until the built-up pressure with the assistance of column 
H overcomes the resistance of the boiler pressure. Then column H will 
fall, the air vent will open and allow escape of some air, thereby relieving 
part of pressure in the vent trap. Column H will again rise, closing the 
air vent, and this cycle will be repeated. When intermittent venting is repeated 
for a sufficient length of time under excess pressure without admitting raw 
feed water containing gases, all the air will be expelled from the radiation. 

Such a system will continue indefinitely to circulate, due to a pressure 
difference which will be fully equal to that of its normal H ; that is, the pres- 
sure in the vent trap will be less than the pressure in the boiler, by an amount 
equal to an hydraulic column of height H less the resistance of the check 
valve on the drip of this column. 

In modulation systems designed for a stated pressure Pb and open vent 
at head H, the only difficulty occurs where a pressure exceeding Pb is built 
up rapidlj^ before the initial air has been fully expelled. Under such con- 
ditions complete circulation wall not be obtained as rapidly as if steam had 
been generated at a slower rate. 

To overcome the difficulty in expelling air and returning condensation 
to the boilers, where excessive pressure is rapidly generated, as in the use 
of certain grades of bituminous coal, wood, etc., a special high-duty vent 
trap should be employed. In this trap, due to the rise in column H, the 
air vent is automatically closed and an equalizing pipe between the boiler 
and the vent trap is opened, the water under equalized pressure flowing 
by gravity to the boiler, after, which the equalizing pipe is closed and the 
air vent again opened. The two operations taking place alternately, serve 
to vent the system completely of air and also return the condensation to 
the boiler, regardless of the boiler pressure. 

As follows in the discussion of pressure drop in vacuum systems, the 
return mains should be proportioned relatively to the steam mains selected 
for equal duty. This principle applies also to modulation systems. 

The basic proportional sizes of returns to supply mains recommended 
are given in Table 11-4. 

Pressure Drop in Vacuum Systems: The reason for employing a vacuum 
system rather than a modulation system lies in the greater total drop 
obtainable from a given initial pressure P above, to terminal pressure p 
below atmospheric, thereby obtaining circulation through greater resistance 
due to long pipe runs and lack of grade for gravity flow of condensation. 

120 



Table 11-4. Relative Proportions of Steam Supply and Return Mains in 

Modulation Systems 



Supply main 


Dry return main 


Return riser 


Wet return 


1 

11^ and 2 

2J4 


54 

1 
1)4 


1 


1 

IK2 


3 and 3V2 

'1 

A]4 and 5 

6 " 


\y2 

3 


1)^ 

2K 


13/2 
1,4 

lJ/2 

2 


7 and 8 
9 and 10 
12 


3 and 3}^ 

4 and W2 

5 


3 
4 


2 
9 

2H 



Lowering the terminal pressure p by mechanical exhaustion in return 
mains (the vacuum system) allows greater pressure drops through each of 
the series of resistance. 

In good vacuum system practice, the total drop between source of sup- 
ply through the inlet valve of the farthest radiator on the system should be 
that between available initial and atmospheric pressure, so that normally 
the pressure in the radiator will be at or very slightly below that of the at- 
mosphere. The pressure drop p4 of the return trap may usually be two to 
three times that permissible in a well designed modulation system. The 
drop ps in the vacuum return lines, if graded in direction of flow, may equal 
that in the supply mains of the system under consideration, and if it be neces- 
sary to elevate the condensation at one or more vertical lifts in order to ob- 
tain horizontal grade toward the vacuum pump, this (within limits of tem- 
perature of condensation) may be obtained by increasing the displacement 
of air and vapor by the pump. In systems where the high vacuum neces- 
sary to lift the condensation at one or more points, would occasion a need- 
lessly high vacuum in that portion of return system which has a gravity 
flow, the degree of vacuum may be reduced by means of special vacuum 
controlling apparatus which provides for continuous discharge of condensa- 
tion and also for a reduction of degree of vacuum between the inlet and 
outlet of the apparatus. (See Chapter 15, page 176, for description of such 
apparatus.) 

In general, owing to greater pressure drop, a vacuum system will not 
require as large mains, branches to, and inlet valves of radiation as needed 
for a modulation system. Likewise, the radiator traps and return mains 
may be smaller for similar sized units of radiation provided radiator traps of 
high efficiency are properly installed to prevent leakage of steam to return lines. 

Return traps on radiators should be proportioned for a pressure dif- 
ference of between 3^ and l^lb. depending upon the condition of the partic- 
ular problem. 

Return mains should be proportioned relatively to the steam mains 
selected for equal duty by the table of comparative sizes (Table 11-5), 
allowing additional areas, however, where there is probability of high tem- 
perature in the outlet end of returns, due to steam leakage of return traps 

121 



or lack of vapor condensation occasioned by thoroughly insulated mains 
retaining the heat in the water passing through the radiator traps. 

Where high vacuum for lifts increases the volume of vapors and gases 
to be removed, at least one size larger return mains should be used. 

Such degree of partial vacuum should be carried by properly propor- 
tioned pump displacement as to cause a partial vacuum equal to the selected 
pressure difference (P4) through the most remote return traps on the system. 
In proportioning pump displacement for vacuum systems, the most complex 
problem is that of proper allowance for the amount of vapor and air. Pres- 
sure below atmosphere in any part of the system is liable to induce invisible 
air leaks. For full efficiency of radiation, the temperature of condensation 
passing through return traps must be close to that due to the steam pressure 
in the radiator. 

Part of the hot water, when flowing into lower pressure in the return 
line, flashes into vapor of high specific volume. The amount may be deter- 
mined by inspection of the re-evaporation chart shown on page 157. 

Some of this vapor will be condensed on the way to the vacuum pump, 
the vohmae dependmg upon whether or not the returns are insulated and 
also upon the amount of radiation, due to the length of the return pipe. 
It must be borne in mind that the vacuum or degree of partial pressure in 
the return line cannot exceed that corresponding to the temperature of the 
water of condensation. 

Inleakage of air through even minute imperfections in piping causes an 
increase of volume to be handled proportionately as the absolute tempera- 
ture of the air at inleak is to the absolute temperature in the return system, 
plus expansion from that volume at atmospheric pressure to that of vacuum 
pressure. 

As explained in Chapter 13 on Vacuum Pumps, it is frequently possible 
to take advantage of some condensing medium such as cool air for ventila- 
tion, or water which must be warmed for cooking and washing, boiler feed, 
etc., and use this medivuai for cooling and condensing the air and vapor 
to decrease its volume on the way to the pump. 

Table 11-5. Normal Relation of Return Mains and Risers to Supply Mains 
Caring for Equal Amounts of Steam in Vacuum Systems 



Horizontal Horizontal Vertical Gravity drip vertical Outlet at heel of risers 2 J^-in. and under, less 

supply mam return return ^^^^ ^.^ ^^^^.j^^ j^j^j^ 3^^ j^^ q^^^, ^2 stories or Over 2I^-in. riser 1-in. 

Iy4-in. and less •x4-in. /4-ii'- vertical outlet increasing in horizontal run to l^-in. 

1/^ and 2-in. 1 % Horizontal gravity drips Number of i?4' or I-in. outlets which 

Q ITqi/ • 1/ 1/ graded at least J^|-in. in may be carried on one horizontal 
A ^1/ j'" • / ^^^^ ^^'^ usually capa- run when graded '4-in. in 10 feet, 

i, i /2 ana 5-m . _ 1/^ ble of caring for the num- provided radiation on steam riser 

o and ^-in. _ o - ber of ?'4 or 1-in. outlets does not drain as in one -pipe 

8and9-m. 3 2I2 as follows: system 

10-m. 3I/9 3 



12-in. 4 3J4 Size 

14 and 1.5-in. 4}4 i 



horizontal 



16 and 17-in. .5 1}4 1^-in. 

18 and 20 in. 6 5 IJ^ 



122 



No. of 34-in. 


No. of 1-in. 


outlets 


outlets 


12 


6 


18 


12 


30 


18 


60 


36 


100 


.50 



5H' 



3000" 



5000' 



2V2 



100 '8" 



3'/2 



NO 



4^ 



Trr-r- 



6000' 



Sizing of Piping: The use 

of the tables in sizing piping may 
best be explained by the following 
examples. 

Vacuum System: Assume a 
central steam generating plant for 
a group of buildings, Figure 11-3. 

In the problem here presented ^ 

are a boiler house and three de- 
tached buildings A, B and C, 
connected by a system of well- 
covered mains in a tunnel. 
Through these mains it is desired to con- 
vey 6000 lb. of steam to building A, 5000 
lb. to building B, and 3000 lb. to building 
C, per hour, with a pressure drop from 
16-lb. absolute in the boilers to or near 
atmospheric pressure just beyond the main 
valve in each building. 

Good covering, still air at about 70 
deg. and proper drainage are assumed. 

The total steam requirement per hour 
of buildings A, B and C is 14,000 lb. 

The longest run of main is from the 
boiler house to building C and without 
allowance for fittings is 880 ft. 

In estimating the sizes of pipes by the 
use of Table 11-2 it is necessary to first 
find the drop of pressure per 1000 ft. 
and then to find the corresponding quan- 
tity of steam flowing through the pipe 
for a drop in pressure of 1 lb. for this dis- 
tance of 1000 ft. 

The pressure drop varies directly as the length of a pipe, and the weight 
of steam discharged through a pipe varies directly as the square root of the 
pressure drop. We therefore multiply a given weight of steam by 



4'/2 



20 , 



50 



Fig. 11-3. Illustrat- 
ing the problem of siz- 
ing steam and return 
lines for group of build- 
ings as described in the 
text 



Boiler 



V- 



1 lb. X (the tabular pressure drop per 1000 ft.) 



The given pressure drop per 1000 ft. 
to find the equivalent weight of steam at 1-lb. drop per 1000 ft. 

The assumed drop in pressure is 16 — 14.7 = 1.3 lb. per sq. in. 
For a given total drop of 1.3 lb., the drop per 1000 ft. is 

^Q X 1000 = 1.48 lb. 

The first section of pipe to A conveys 14,000 lb. per hr. and the cor- 
responding weight of steam at 1-lb. drop per 1000 ft. is 



y 1.48 



X 14,000 = 11500 lb. 



123 



Keferring to Table 11-2 we find that to convey 11500 lb. per hr. at a 
pressure drop of 1 lb. per 1000 ft. requires a 12-in. pipe. 

The second section of main from A to B conveys 8000 lb. per hr. at 
a pressure drop of 1.48 lb. per 1000 ft. Using the same reasoning we find 
that the corresponding weight of steam at 1-lb. drop per 1000 ft. is 



V 



^ X 8000 = 6600 lb. 



1.48 

From Table 11-2 the pipe size is found to be 10-in. 

Similarlv the branch from B to building C convevs 3000 lb. per hour 
at 1.48 lb. drop per 1000 ft. 

The corresponding weight at 1 lb. drop per 1000 ft. is 



V 



X 3000 = 2460 lb. 



1.48 

And from Table 11-2 the pipe size is 7-in. 

The total steam to be carried will, however, be in excess of 14000 lb. 
by the amount condensed in the mains. 

The pressure drop for pipe friction will be less than 1.3 lb. by the amount 
necessary for initial velocity. 

The length of run equivalent to the lineal run plus the added allowances 
for fittings as shown in Table 11-3 will be materially in excess of 880 ft. 

It is therefore evident from an inspection of the plan that the above 
trial sizes may be too small and that it will be advisable to assume an increase 
of one size of pipe above those previously assumed, in all cases where there 
is a considerable number of fittings etc. This is true, in this problem, in 
the first section of the main. 

The trial sizes will then be, 14-in. for the run to branch A; 10-in. to 
branch B and 7-in. to C. 

Condensation AUoumnces: For 425 ft. of 14-in. main from the boiler 
to branch A. 

From Table 11-2 we find the square feet of surface per lineal foot of 
pipe to be 3.9 sq. ft., this equals 1657.5 sq. ft. for the 425 ft. of 14-in. main. 
To this should be added 5 per cent for radiation from fittings making approxi- 
mately 1740 sq. ft., radiating 50 B.t.u. per sq. ft. per hr., when the tempera- 
ture drop is 216 deg. — 70 deg. = 146 deg. Multiplying 50 (B.t.u.) by 
1740 (sq. ft.) and dividing by 968 gives the total condensation for the 14-in. 
main, which equals approximately 90 lb. 

The 10-in. main condenses 2.82 (sq. ft. of surface per lineal ft.) X 200 
(ft.) X 50 ^ 968 or 29.2 lb. + 5 per cent for fittings = 31 lb. 

The 7-in. main condenses 2 X 255 X 50 ^ 968 or 26.4 lb. + 5 per 
cent for fittings = 28 lb. 

It is evident that the condensation of the branches will be a small 
portion of the total quantity of steam carried by the main or branches. 
Estimating by comparison with branch to C, it is obvious that branches 
to A and B will condense hardly more than 40 lb. per hour each. 

This gives us the total quantitv of steam to be carried by the 14-in. 
main; 14000 + 90 + 31 + 28 + 40'+ 40 = 14229 lb. per hr. 

124 



The 10-in. main carries 8000 + 31 + 28 + 40 = 8099 lb. per hr. 

The 7-in. branch to C carries 3000 + 28 = 3028 lb. per hr. 

Pressure Drop for Initial Velocity: In a 14-in. main conveying 18970 

lb. per hour the velocity is 7060 ft. per min., from Table 11-2. At 14229 lb. 

14229 
per hour the velocity will be " x 7060 = 5300 ft. per min. 

From Table 11-1 we find that 0.0625 lb. is recjuired to accelerate the 
steam from rest in the boiler to a velocity of 5520 ft. per min. in the main. 

For 5300 ft. per min. the drop is therefore [^^Vx 0.0625 lb. = 0.06 lb. drop 

velocity head. The residual pressure available for overcoming friction 
in the mains and branches is 1.3 — 0.06 = 1.24 lb. per sq. in. 

Referring to Table 11-3 we find the equivalent resistance in feet of 
straight pipe to be added to the run for friction in fittings, etc. The various 
quantities are tabulated on page 126 and the summation of the quantities 
gives the eciuivalent length of pipe for each section and for the total. We 
find that the revised ecjuivalent run is now 1559 ft. and with a given drop of 
1.24 lb. in the total run, the drop per 1000 ft. is 0.796 lb. In the last column 
s found the revised actual pressure drop for each section. 

The pressure drop through a pipe varies as the sciuare of the weight 
flowing through it. If we know the weight of steam discharged through a 
pipe w th 1-lb. drop per 1000 ft. (as from Table 11-2) and wish to find the 
drop of some other weight (as the weights in column cj on next page) we can 
obtain it by applying this law. The square of the ciuotient of the given 
weight divided by the tabular weight, times the tabular drop equals the 
drop for the given quantity (column s). 

The total drop of l.l6 lb. shown in the table is as close to the desired 
drop as can be expected with commercial sizes of pipe. If the deviation 
had been greater, one or more of the trial sizes would have to be altered 
to bring the total drop nearer that desired. Inspection of column s will 
show in which portion or portions of the main the drop per 1000 ft. is farther- 
est from the average of 0.796 lb. 

It is this section or sections that should be refigured. 

The pressure available for friction in the branches is the difference 
between the total available drop of 1.24 lb. and the amount already utilized 
in the main up to the junction with the branch in question. 

The procedure for determining branch sizes is exactly the same as 
for the mains; assuming one size larger than the calculated trial size, adding 
condensation and allowance for fittings and checking to see that the actual 
drop to the building is close to the permissible drop. 

The drop in the branch to A is 1.24 lb. - 0.518 lb. = 0.722 lb. Di- 
viding this by 255 ft. (actual length of run to A) X 1000 gives 2.83 lb. 
drop per 1000 ft. in this run. 

The corresponding weight at 1-lb. drop per 1000 ft. is: 

^ ^ly X 6000 (lb.) =3560 lb.; requiring (from Table 11-2) 8-in. pipe. 
2.8D(ib.) 

The drop in the branch to B is 1.24 lb. - 0.768 lb. = 0.472 lb. Dividing 

125 



V. 









Table 11-6 








Section 


Trial 

size 

pipe 

ra 


Actual 

length 

n 


Equivalent 

length 

for 

fittings 




Total 

equivalent 

length 

(n+o) 
p 


Weight 

of 
steam 


From 
Table 11-2 

Weight 
passed by 
trial size at 
1-lb. drop 
per 1000 ft. 
r 


Actual Actual 
pressure drop in 
drop per section 

1000 ft. of main 

1 — 1 xlflb.) xs 

\ "■ / 1000 

s t 


Boiler house 
to branch A 


14-in. 


42.5 


1 Gl. V. 

160 ft. 
6 ells 
318 ft. 


903 ft. 

lb. 


14229 
per hr. 


18970 
lb. per hr. 


. 564 lb. .518 lb. 




478 ft. 




Branch A 

to 
branch B 


10-in. 


200 


run of 
reducing 
tee 
24 ft. 


224 ft. 


8099 lb. 
per hr. 


7680 lb. 
per hr. 


1.12 1b. .25 1b 




Tot. 21 ft. 




Branch B 

to 
bldg. C 


7-in. 


25.'5 


1 Gl. V. 82ft, 

3 ells 78 ft. 

run of 

reducing 

tee 17 ft. 


432 ft. 


3028 lb. 
per hr. 


3155 lb. 
per hr. 


.921 lb. .398 lb. 




Tot. 177 ft. 






Total 


equiv. 


main 1.559 ft. 








Total drop 1.166 1b. 



this by 155 times 1000 gives 3.04-lb. drop per 1000 ft. in this run. The 

corresponding weight is i ^ x 5000 (lb.) = 2880 lb. requiring a 7-in. pipe. 

\3.04 

Assume for the first trial, one size larger than figured above, to take care 
of the comparativelj^ large number of fittings, etc. The branch to A will 
be 9-in. and to B, 8-in. 

The estimated quantities of condensation are close enough for use in 
sizing these branches. The total quantitv carried bv branch to A is there- 
fore 6000 + 40 = 6040 lb. and by branch to B, 3000 + 40 =3040 lb. 

Table 11-7 



Section 



Trial 
size 
pipe 



Fittings 



Total 

equivalent 

length 



Weight 

of 

steam 



Weight 
passed 
by trial 
size with 
1-lb. drop 
per 1000 ft. 

y 



Actual 

pressure 

drop 

per 1000 ft. 



(-) 



Actual 
drop 



X 1 (lb.) in 

branch 
wXz 



Drop 

in 
main 

to 
branch 



Total 
drop 
boiler 
house 
to bldgs. 



Branch 
A 



9-in. br. tee 68 ft. 2 ells 497 ft. 6040 1b. 5900 1b. 1.04 1b. 
70 ft. Gl. v. 104 ft. 



.52 lb. .518 lb 1.038 lb. 



Total 242 ft. 



Branch 
B 



br. tee 63 ft. 2 ells- 374 ft. 
62 ft. Gl. v. 94 ft. 



5040 1b. 4400 1b. 1.311b. .49 1b. .768,1b. 1.2581b. 



Total 219 ft. 



12b 



Since the total drop from the boilerhouse to the building in each case 
is not far from 1.24 lb., or is at least as close as commercial sizes of pipe 
will allow, the trial sizes of 9-in. to A and 8-in. to B are correct. 

The sizes of return mains should be based upon the sizes of the corre- 
sponding steam mains in the foregoing example. 

By referring to Table 11-5 we find as follows: branch returns from 
buildings B and C are respectively 3-in. and 2J2-iii- to the junction, where 
they increase to 3J/2-in-, continuing this size to the point where the 3-in. 
return from building A joins the above. Increase the return here to A}/2,-y(\. 
and continue this size to the vacuum pump in the boiler house. 

Long computations such as the above are required only in connection 
with extensive distributing systems, where the cost of one size larger pipe 
becomes important. 

For general use in sizing mains, branches and risers for both modulation 
and vacuum systems. Tables 11-8 A. B, C and D will be found sufficiently 
accurate if used with discretion. They are based upon 75 per cent of the 
values of Table 11-2 and will cover an ordinary amount of valves, fittings, 
etc., if globe valves are excluded. 

In the use of Tables 11-8 A, B, C and D the permissible pressure drop 
between the inlet of the supply main and the farthest radiator determines 
the alphabetical sub-division of the table which is to be used. Table 23-7 
in Chapter 23 gives a list of pressure differentials, which will be found reason- 
ably accurate for various types of modulation and vacuum systems under 
ordinary conditions. 

The following rules should be employed to determine which column 
of length of run should be used for horizontal or vertical pipes in the alpha- 
betical sub-division selected- 

1. For horizontal supply pipes, find the total run in feet along the pipe 
from the source to the farthest radiator and use the corresponding column 
in the table. 

2. For sizing up-feed risers, add -yis of the length of the vertical pipes 
to the total run found by Rule 1, and use corresponding column in table. 

3. For sizing down-feed risers deduct yV of the length of the vertical 
pipes from the total run found by Rule 1, and use the corresponding column 
in the table. 

4. The sizing of supply run-outs, especially those in which the con- 
densation must flow by gravity in the opposite direction to the steam current, 
calls for special consideration and will be discussed in Chapter 12 on Critical 
Velocities in Radiator Run-outs. 

5. The sizes of return mains and run-outs should be based on the sizes 
of supply mains, which will take care of a similar quantity, and are found 
by reference to Table 11-5. For convenience, the correct sizes of return 
mains and risers, for a given number of pounds of condensation, length of 
run and pressure differential, are also contained in Table 11-8 A, B, C and D. 

Modulation System: lu sizing piping for modulation systems, long com- 
putations such as described under vacuum systems are not necessary. 
The Tables 11-8 A to 8 D are sufficiently accurate for ordinary conditions. 

127 



Table 11-8. Ratings of Supply and Return Mains in Pounds of Steam per Hour, 

for Various Pressure Drops from Initial Pressure of 16 lb. Absolute, 

when in Horizontal Runs of from 300 to 1,000 ft. 

These tables are found by taking 75 per cent of the values of straight pipe given in Table 11-2, to 
cover an ordinary number of valves and fittings, entrance velocity and other resistances to the flow of steam 









A.— l/g-lb. Drop 


in Pressure 






Pipe sizes for modulation systems 




Length of run in feet 






Return (from table 11- 4) 


Steam supply 


300 


400 SOO , 


750 


1,000' 


Return- 

riser 


Dry return main 




Rating in pounds of steam per 


hour 




Va" 


H" 


1" 


7.08 


6.12 5.48 


4.48 


3.88 


%" 


1" 


Ik" 


16.9 


14.6 13.1 


10.7 


9.25 


1" 


IM" 


VA" 


26.6 


23. 20.6 


16.85 


14.6 


1" 


Ik" 


2" 


55.4 


47.8 42.9 


35. 


30.35 


Ik"' 


Wz" 


2y2" 


91.5 


79. 71. 


57.8 


.50.2 


iH" 


I'A" 


3" 


169. 


146. 131. 


107. 


92.5 


iy2" 


VA" 


3K" 


249.5 


215.5 193,4 


157.7 


136.5 


IVo" 


2" 


4" 


353.5 


305. 274. 


223.5 


193.6 


9" 


2J/2" 


5" 


642.5 


.554. 198. 


406. 


3.52. 


2W 


3" 


6" 


1043. 


900. 808. 


660. 


572. 


3" 


3" 


J 


1.525. 


1318. 1185. 


965. 


836. 


3" 


3K" 


8" 


2130. 


1840. 1650. 


1347. 


1168. 


33^" 


4" 


9" 


2855. 


2465. 2215. 


1806. 


1564. 


3^" 


4M" 


10" 


3835 . 


3315. 2975. 


2425 , 


2110. 


4" 


5" 


12" 


6060. 


5230. 4700. 


3835. 


3320. 


5" 


6" 


14" 


9175. 


7920. 7120. 


5800. 


5030. 


5" 


6" 


16" 


11320. 


9780. 8780. 


7160. 


6210. 


9" 


7" 


18" 


1.5350. 


13280. 11900. 


9720. 


8410. 


7" 


8" 


20" 


20100. 


17400. 15600. 


12720. 


110.30. 



B — %-lb. Drop in Pressure 



Pipe 


sizes for modulation systems 


Length of run in feet 


Return (from table 1 1-4) 


Steam supply 


300' 


400' 500' 


750' 


1,000' 


Return 

riser 


Dry return riser 


Rating in pounds of steam per hour 


k" 
k" 

1" 

1" 


k" 
1" 

VA" 
VA" 


1" 
Ik" 

VA" 
2" 


10.03 
23.9 

37.7 
78.4 


8.67 7.75 

20.7 18.5 
32.6 29.2 

67.8 60.7 


6.34 
15.1 
23.8 
49.6 


5.48 
13.1 
20.6 
42.9 


Ik" 

VA" 
VA" 
VA" 


VA" 
VA" 
VA" 

2" 


2A" 

3" 

3^" 

4" 


129.5 
239. 
353. 
510. 


112. 100.3 
207. 185. 
305.5 273. 
433. 387. 


81.8 
151.2 

223 
316 ! 


71. 
131. 
193.4 

274. 


2" 
2 A" 
3" 
3" 


2%" 
3" 
3" 
3A" 


5" 

6" 

7" 
8" 


910. 
1478. 
2160. 
3015. 


786. 704. 
1280. 1142. 
1870. 1670. 
2610. 2335. 


574. 

933. 
1365. 
1905. 


498. 

808. 
1185. 
1650. 


3J^" 
3A" 
4," 
5" 


4" 

iA" 

5" 

6" 


9" 
10" 
12" 
14" 


4040. 

5430. 

8580. 

13000. 


3495. 3125. 

4700. 4200. 

7420. 6640. 

11250. 10060. 


25.50. 
3430. 
5430. 
8220. 


2215. 
2975. 
4700. 
7120. 


5" 
6" 

7" 


6" 

7" 
8" 


16" 
18" 
20" 


160,50. 
21750. 
28500. 


13890. 12400. 
18820. 16820. 
24650. 220.50. 


10130. 
13750. 
18000. 


8780. 
11900. 
15600. 



128 



Table 11-8 — Continued 
C — 54-lb. drop in pressure 



Pipe sizes for modulati 


on systems 

Steam 
supply 




Length of run in feet 


Pipe sizes 

Steam 
supply 


for vacuum systems 


Return (from table 

11-4) 


300' 


400' SOO' 750' 1000' 


Return (from table 
11-5) 


Return 
riser 


Dry ret. 
main 


Ratings in pounds of steam per hour 


Horiz. 


Vert. 


H" 
1" 
1" 


H" 
1" 

IM" 
IH" 


1" 

IK" 

lA" 

2" 


14.18 
33.8 
53.3 

110.8 


12.28 10.98 8.95 7.75 
29.25 26.2 21.35 18.5 
46.2 41.3 33.7 29.2 
96. 85.8 70.3 60.7 


1" 

IH" 

n" 


K" 
Vi" 

1" 

1" 


H" 
H" 
H" 
H" 


VA" 
VA" 

VA" 


I'A" 
I'A" 

2" 


2J^" 
3" 

W2" 
4" 


183. 
338. 
498. 
707. 


158.6 142. 115.8 100.3 
292.5 262. 213.5 185. 
432. 386.5 315. 273. 
612. 548. 447. 387. 


2A" 
3" 
3A" 
4" 


lA" 
lA" 

2" 


1" 
IM" 
IM" 
lA" 


2" 
2M" 
3" 
3" 


2y2" 

3" 
3" 
3^" 


5" 
6" 
7" 
8" 


1285. 
2085. 
3050. 
4260. 


1113. 997. 813. 704. 
1808. 1620. 1320. 1142. 
2645. 2365. 1930. 1670. 
3690. 3300. 2695. 2335. 


5" 
6" 
7" 
8" 


0" 

~2A" 
2W 
3" 


lA" 

2" 
9" 

~2A" 


33^" 

sy2" 

4" 
5" 


4" 
iA" 
5" 
6" 


9" 
10" 
12" 
14" 


5720. 

7675. 
12130. 
18360. 


4945. 4430. 3610. 3125. 

6650. 5950. 4850. 4200. 
10500. 9400. 7660. 6640. 
15900. 14220. 11600. 10060. 


9" 
10" 
12" 
14" 


3" 

3A" 

4" 

43-^" 


2A" 
3" 
3J4" 
4" 


5" 
6" 

7" 


6" 
7" 
8" 


16" 
18" 

20" 


22620. 
30750. 
40250. 


19610. 17560. 14310. 12400. 
26600. 23800. 19420. 16820. 
348.50. 31200. 25420. 22050. 


16" 
18" 
20" 


5" 
6" 
6" 


iA" 

5" 
5" 



D— 1-lb. drop in pressure 



Pipe sizes for modulation systems 



Return (from table 
11-4) 



Return 


Dry ret. 


riser 


mam 


H" 


H" 


%" 


1" 


I" 


Ik"' 


I" 


IM" 


IM" 


^A" 


lA" 


I A" 


lA" 


lA" 


lA" 


2" 


9" 


2A" 


2A" 


3" 


3" 


3" 


3" 


W2" 


5A" 


4" 


W2" 


^A" 


4" 


5" 


5" 


6" 


5" 


6" 


6" 


7" 


7" 


8" 



steam 
supply 



1" 

IH" 
lA" 
2" 

2A" 
3" 

3H" 
4" 

5" 
6" 
7" 
8" 

9" 
10" 
12', 
14" 

16" 
18" 
20" 



Length of run in feet 



400' 



500' 



750' 



Ratings in pounds of steam per hour 



20.2 17.4 
47.8 41.4 
75.4 65.4 

157. 136. 

259. 225. 

478, 414. 

706. 612. 

1000. 867. 

1820. 1575. 

2955. 2565. 

4320. 3750. 

6030. 5230. 

8080. 7020. 

10870. 9425. 

17160. 14900. 

26000. 225.50. 

32050. 27810. 
43500. 37720. 
57000. 49400. 



15.5 

37. 

.58.3 

121.5 

202. 
370 
546. 

774. 

1410. 
2282. 
3340. 
4660. 

62.50. 

8400. 
13300. 
20130. 

24800. 
33620. 
44100. 



12.65 10.98 

30.2 26.2 

47.6 41.3 

99. 85.8 

163.6 142. 

302. 262. 

446. 386.5 

632. 548. 

1150. 997. 

1867. 1620. 

2730. 2365. 

3810. 3300. 

5110. 4430. 

6860. 5950. 

10850. 9400. 

16400. 14220. 

20250. 17560. 
27450. 23800. 
36000. 31200. 



Pipe sizes for vacuum systems 



Steam 
supply 



1" 

Ik" 

\A" 



2A" 
3" 

■iA" 

4" 

5" 
6" 

7" 
8" 

9" 
10" 
12" 
14" 

16" 
18" 
20" 



Return (from tadle 

11-5) 



Horiz. 



1" 

1" 

Ik" 

lA" 
lA" 

2" 

9" 

2A" 
2A" 
3" 

3" 

4" 
434" 

5" 
6" 
6" 



Vert. 



?4 
k" 
k" 
k" 

1" 

Ik" 
Ik" 

lA" 

2" 
2" 
2A" 

2A" 
3" 

3A" 
4" 

i.A" 

5" 
5" 



129 



The total quantity of steam to be supplied per hour at the time of maxi- 
mum normal heating effect being a known factor and the total maximum 
pressure drop in the heating system being determined for this period, the 
pressure drop in the supply main must be so chosen that the pressure to be 
carried on the boiler will exceed by a safe margin the sum total of resistances 
between the boiler and the outlet of the vent valve. 

For an illustration, assume a typical modulation system which requires 
500 lb. of steam per hour for maximum normal heating effect. The length 
of run is assumed to be 300 ft. and the boiler pressure is not to exceed 
i^-lb. gauge. 

To find the proper size of supply main to meet these conditions, the 
pressure drops from p to pe as described in the discussion of pressure drop 
in modulation systems. Page 116, must be determined, before the permis- 
sible pressure drop p^ in the supply main can be ascertained. 

During maximum normal heating effect we find the pressure drop from 
p to p 6 to be as follows: 

p = constant at atmospheric pressure = 0.000-lb. gauge 

pi = pressure drop through vent check valve (intermittent 

at that period) = 1/20 lb. = 0.050 " 

Pa = pressure drop through vent valve orifice (negligible at 

that time) = 0.000 " 

ps = pressure drop in return main. Negligible if return has 

proper grade = 0.000 " 

p4 = pressure drop through orifice of radiator trap, which for 
the given condition will be the maximum tabular value 

of Vs lb.= 0.125 " " 

p5 = pressure drop through radiator. Negligible at that 

time = .0.000 " " 

pe = pressure drop through radiator valve will be the maxi- 
mum tabular value for the given period, 3^ lb. =0.125 

Total drop p to pe = 0.300 '' || 

The pressure to be carried on the boiler = )^ lb 0.500 

Pressure drop p to pe = 0.300 

Difference of pressure available 0.200 

Bearing in mind that in addition to the pressure drop p? in the supply 
main, we must consider also the pressure drop ps to impart initial velocity, 
we readily see that a pressure drop of 34 lb- in the supply main would be 
unsafe and we, therefore, select the 3^-lb. drop in the supply main p? as the 
basis for determining the size of pipe required. 

We find by referring to Table 11-8 A that a 5-in. main is necessary to sup- 
ply 500 lb. of steam with 3^-lb. drop in pressure in a run of 300 ft. 

We now have to determine the head or pressure drop ps necessary to 
impart initial velocity to the steam. 

From Table 11-2, we find S, the cubic ft. per pound of steam at 15.3 
lb. absolute (assumed boiler pressure) is very nearly 26.27. 

Converting the total steam required in pounds per hour into cubic 
feet per minute 

130 



500X26.27 13135 _,„„ ^.„ „ 
y^ = ^„ = 218.9, or, say, 219 cu. ft. 

By referring to Table 11-2, column 3, we find the linear feet per cubic 
foot volume, which for a 5-in. pipe is 7.22. 

Multiplying 219 by 7.22 we obtain the velocity in feet per minute of 
the steam to be 1582 ft. 

We now determine the pressure drop ps necessary to impart initial 
velocity and by referring to Table 11-1 we find for a 2500-ft. velocity, a pres- 
sure drop of 0.01 lb., which for a 1582-ft. velocity would be approximately 
0.009 lb. per sq. inch. 

The total pressure drop between the boiler and the outlet of the vent 
valve then becomes: 

Pressure drop p - pe as stated before = 0.300-lb. gauge 

Pressure drop p? in main J/g lb. = 0.125 " " 

Pressure drop p^ to impart initial velocity = 0.009 

Total pressure drop = 0.434-lb. gauge 

We find an effective differential in pressure between the boiler pressure 
and the pressure losses in the sytem of 0.500 —0.434 = 0.0661b. gauge, for 
maintaining circulation in the system during the period of maximum 
heating effect. 

This proves that for the above condition, the 3^-lb. drop in pressure in 
Pt is the proper basis for selecting the table to be used, and this being de- 
termined, the intermediate sizes of the main and branches are taken from same. 

The sizing of run-outs requires special consideration as described in 
detail in Chapter 12, Critical Velocities in Radiator Run-outs. 

The sizing of returns involves the same procedure with modulation 
systems as outlined before in the discussion of sizing of piping for vacuum 
systems. The size of the return depends on the size of supply for an equal 
duty. TBy referring to Table 11-4, we find that the size of return correspond- 
ing to a 5-in. supply main is 23^2 in., which is the size we select. 

Taking care of the condensation in the steam main at the far point is 
often found necessary in modulation systems in which case the pipe sizes 
must be increased toward the end of the run, beyond the tabular values, to 
take care of the reduction in effective Eirea of the pipe due to the condensa- 
tion being carried along with the steam. 

A further reason for increasing the sizes of the pipes toward the end of 
the run is to compensate for the air carried along with the steam in the pipes, 
which, if not properly relieved, will retard the circulation of steam to a great 
extent. 

Air relief connections must be provided at the ends of the runs, through 
thermostatically actuated return traps into the nearest dry return, in all 
cases where gravity drips are made into a wet drip line. 



131 



CHAPTER XII 

Critical Velocities in Radiator Run-outs 

THE velocity in a nearly horizontal pipe in which the condensation is to 
be drained by gravity in the opposite direction to the flow of steam 
above it, becomes critical, when it reaches such rate that any velocity 
increase will cause the condensation to be swept upgrade against gravity. 
The need has been apparent to heating engineers of definite information 
regarding this critical velocity of steam in branch run-outs to radiation in 
which condensation must be drained in a direction opposite to steam flow. 

Individual opinion based on experience regarding velocity permissible 
at given slope without danger of noise due to surging, varies fully 300 per cent. 

Many modern buildings have very limited space in which to run pipes 
between the finished floor and the main beams and fireproof construction. 
There are many valid objections to exposing the run-outs above the finished 
floors, and the question frequently arises as to the proper size and grade for 
such pipes in the available space beneath the finished floor. 

Fundamentally the size of pipe for a given radiator run-out is de- 
pendent on the maximum number of heat units to be conveyed in a given time. 
The latent heat content per cubic foot of steam at the range of pressures usual 
in modern "low-pressure" heating is least at the lower pressures. Denser 
steam at higher pressures undoubtedly sets up greater wave-forming friction 
of steam over surface of the condensation and will sweep the water up the 
slope at a slightly lower steam velocity than that at which the condensation 
will flow against the current of less dense steam. These facts in a measure 
offset each other and the small error in the final result will have less effect on 
the problem than the inaccuracies of grade liable to exist despite any reason- 
able care in erection. 

In an endeavor to fix the critical velocity, a carefully conducted series 
of tests has been made. The first of this series was with glass tubes, to 
determine visually just what took place when steam at various velocities 
passed over its condensation in pipes graded against the steam flow. The 
result of this series was very instructive in determining the effect of velocity 
and what to look out for in subsequent tests. The second tests were with 
commercial pipe of 1 in., 1)^ in., IJ/2 ii^- ^^id 2 in. sizes, each 18 ft. long; 
each pipe being tested at uniform grades of 34 in., I/9 in., 1 in. and 13^ in. 
in 10 ft. 

It was found that the difference in critical velocity in the various sizes 
of pipe under test differed less at the same slope than the errors incidental 
to careful observation. In consequence of the fact that the size of pipe had 
no direct relation to critical velocity, only one size was tested at a grade of 
3 in. in 10 ft. to complete the curve of velocity at slope. 

The result of these tests upset some preconceived theories and estab- 
lished some facts that appear to be fundamental. These established facts are : 

1. That the size of the pipe has no visible relation to the critical ve- 
locity, which was practically the same in all sizes tested. 

132 



2. That the normal vokime of condensation in a covered pipe as compared 
with an uncovered pipe, had no effect on the critical velocity. In fact, increase 
in condensation up to the point where the volume of water limited the free 
area for steam and made a material difference in velocity, the condensation 
continued to flow as with normal condensation. 

3. That greater or less length of run if at uniform slope makes no ma- 
terial difference. The controlhng velocity is that in the first foot or two of 
pipe, and if the velocity existing there is above critical, it will sweep the 
condensation to the high end. In fact, increase in condensation up to the 
point where the volume of water limited the free area for steam and made a 
material difi'erence in velocity, caused no change in flow of condensation. 

4. That the direction of flow in the vertical supply riser to which the 
run-out is connected, will have a slight effect on the critical velocity in the 
run-out. The critical velocity is lower in a down-feed than in an up-feed 
riser. This is due to the change in direction of the highest velocity steam 
striking the run-out on the lower side and acting on the condensation which 
is endeavoring to flow in the opposite direction. 

The most surprising fact demonstrated during these tests was the rap- 
idly diminishing efi"ect of a slope greater than 1 in 120 on critical velocity, 
and the indication from the curves plotted for the entire series, that the 
critical velocity was little, if any, greater at slopes of more than 1 in 40 
than at that slope. It follows from the above that a velocity of steam which 
will sweep up the condensation in a pipe having a grade of 1 in, say, 33 
Avill sweep the condensation upward in a pipe having more grade. 

The practical application of this series of tests must take local conditions 
into consideration. 

The thermal capacity of the mass of iron in a cold radiator, will call 
for a large volume of steam during the heating-up period, and at the same 
time the difference in pressure at the two ends of the run-out will be greatest. 
Consequently the velocity of steam through the run-out will be far greater 




Fig. 12-1. lOustrating greater capacity of largest possible run-out pipe at a minimum grade compared 
with that of smaller pipe at much greater grade. The capacity of 2-in. pipe at grade of ^ § in. in 10 ft. 
is greater than that of a 1-in. pipe at li?^-in. grade in 10 ft. in the ratio of 7.20 to 4..35. Note application 
in limited space where run-out must cross structural frame beam 



133 



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500 600 700 800 900 1000 1100 1200 1300 1400 

Velocity in Feet per Minute 

Fig. 12-2. Critical velocities in feet per minute, of low-pressure steam in radiator run-outs at various 

grades, where condensation flows down-grade against steam. Specific volume of steam, about 26. .5 cu. 

ft. per lb . 

during initial heating-up than during normal maintenance. 

It is during the initial heating-up that the gurgling and hammering of 
condensation in run-outs causes most complaint. It is then that the flow 
of steam is most liable to exceed the critical velocity and sweep the con- 
densation up into the vertical riser pipe to the inlet valve. 

It would be possible to use a run-out of half the area of cross-section 
if the radiator is to be constantly hot during the heating season as compared 
with area of run-out at same grade for a radiator in which there are frequent 
alternations of heating and cooling. Again, there are many installations m 
which a httle noise during the heating-up period would not be considered 
objectionable, while in others the same amount and kind of noise would 
condemn the entire heating system. No fixed rule based on square feet of 
radiation may therefore be made for sizing run-outs in which the condensa- 
tion is normally drained against the flow of steam. 

A few things are evident from these tests and a number must be left 
to the good judgment of the designer of the system under consideration. 

Among the evident things are: 

1. That a uniform grade approximating 1 in. in 10 ft. is about the maxi- 
mum useful limit. That a pipe if uniformly graded when cold is liable to 

134 



1 — \ — 1 — \ — 1 — 1 — 1 — n — ' — 1 — ^ — 1 — 1 — r~i — ' — 1 — 1 — n — i — i — i — i — i — i — \ — n — i 






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t 




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9 10 11 
B. t. u. per Second 



12 13 



20 



Fig. 12-3. B.t.u. per second conveyed in low-pressure steam through radiator run-outs at grades which 
are critical where condensation flows against the current of steam. Critical velocities established by test 
and as shown in Figure 12-2. 

buckle upward in the middle when hot and destroy the uniformity of grade. 

2. That the most constant annoyance will occur when the flow of steam, 
at normal maintenance rate exceeds the critical velocity for the grade at 
which the run-out is laid. 

3. That where noise is permissible during the heating-up period, the 
run-out should be sized and graded so as not to exceed the critical velocity 
during any normal heat maintenance. If so sized there will be little if any 
noise dm-ing the initial period when condensation is being swept on into the 
radiator by a velocity materially in excess of about 1350 ft. per min. There 
will, however, be a considerable noise as the heat capacity of the metal in 
the radiator becomes satisfied and this will continue during the time the 
steam flow is at a velocity of about 1350 ft. per min. until the steam flow falls 
below the critical velocity at the grade of the run-out. 

From the above tests certain practical conclusions may be inferred. 

The practice in sizing run-outs has been based on some relation to 
pressm-e drop or the friction of the steam in the pipe. This more properly 
apphes to mains and risers. 

The pressure drop due to friction in any normal run-out, when velocity 
is low enough to permit the current of condensation to flow against the 
steam, is less than .001 lb. per ft., therefore so slight that it is negligible. 

135 



It would be much more consistent to size run-outs on basis of critical 
flow rather than on pressure drop. 

Tables 1 and 2, based on the following assumptions, may prove of 
interest : 

1. That a sKght noise due to condensation flowing into the radiator 
with the steam during the heating-up period will not be objectionable. 

2. That at maintained rate, the condensation in the vertical rise pipe 
must also flow back against the steam. This is not necessary where bottom 
of the inlet to the radiator is at a higher level than that of the outlet. 

3. That the radiation during maintenance does not condense at a rate 
in excess of 250 B.t.u. per sq. ft. per hour. 

4. That there will be a uniform grade of not less than ^ in. in 10 ft. 
in two-pipe connection and 1 in. in 10 ft. in one-pipe connection. 



Table 12-1. Run-outs for Two-pipe Work Having Grade of Not Less Than ^-^ in. in 10 
ft. Radiator Transmits Not More Than 250 R.t.u. per Sq. Ft. per Hour 
at Maintained Rate. 

Size of pipe 1" 1}4" 1)4" 2" 



Maximum radiation on pipe in sq. ft. 



Horizontal run-out grade 'ig in. in 10 ft 43 72 101 173 

Vertical branch and valve .58 108 144 260 



Fig. 12-2. Run-outs for One-pipe Work Having Grade of Not Less Than 1 in. in 10 
ft. Radiator Transmits Not More Than 250 R.t.u. per Sq. Ft. per Hour 
at Maintained Rate. 

Size of pipe 1" \H" Wi" 2" 

Maximum radiation on pipe in sq- ft. 

Horizontal run-out grade 1 in. in 10 ft 25 .50 68 115 

Vertical branch and valve 35 75 100 170 



1.30 



CHAPTER XIII 

Vacuum Pumps and Auxiliary Equipment 

VACUUM PUMPS are used: 
1. To remove air and other products of condensation from the return 
main where these products cannot be expelled to atmosphere by gravity 
or internal steam pressure alone. 

2. To induce circulation by reducing the pressure in the return main, 
thereby increasing the pressure differential. 

3. To assist in the complete disposal of the products of condensation. 
Experience indicates two successful types of pump for this service^ 

namely, reciprocating steam-driven, and rotating electric-driven. The 
steam-driven pump has efficiency and economy in its favor where steam 
at 30-lb. or greater, absolute pressure, is continuously available and the 
pump exliaust and its contained heat may be fully utilized in the system. 
The electric-driven pump is generally most efficient where exhaust steam 
from the engines and other sources is continuously available in greater 
quantity than is necessary to supply the heating system; in other words, 
where the exhaust from the vacuum pump to waste would be a loss. The 
electric-driven pump is also preferable where the available live steam supply 
has a pressure too low to operate a steam-driven pump. 

Many rotating pumps in which both air and water were handled in 
one chamber have deteriorated very rapidly in service, largely because of 
the grit always present in the condensation. Rotating pumps with one pump 
chamber handling air and vapor and another containing a centrifugal 
impeller for handling the water have proved practical. 

Many variables enter the problem of ascertaining the proper size of 
pump for a given heating system. In the final analysis, good judgment 
based on wide experience in applying a table of probable pump displace- 
ment is of far greater value than any theoretical formula. 

Even for a close approximation, it is necessary to know enough about 
the heating plan in addition to "the square feet of equivalent radiation" to 
be able to estimate the probable maximum volumes in unit of time of both 
water and elastic fluids of condensation, necessary degree of vacuum at the 
pump and discharge head against which condensation must be delivered. 

The volume of water-condensation varies in different installations fully 
40 per cent per square foot of equivalent direct radiation. The volume of 
elastic fluids — air, water, vapor, steam and gases from impurities — also 
varies with the initial and terminal pressures, with the efficiency of the 
radiator traps, with the degree of prevention of inward leakage of air, with 
the probable cooling effect in the return, and with the character of the im- 
purities in the boiler-feed. 

Lifts (see Figure 13-1) in the return call for greater terminal vacuum 
with consequent greater expansion in volume of the elastic fluids, thus calling 
for greater pump displacement. They should, therefore, be avoided if possible. 

Discharge head on reciprocating pumps handling water and air has the 

137 



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138 



effect of increasing clearance and slip and thereby 
decreasing the effective displacement. 

A discharge head of more than one added 
atmosphere on reciprocating pumps is best 
handled by separating the water and gases and 
removing them independently tlirough 
two separate pumps. 

For slip in reciprocating wet-vacuum 
pumps it is seldom safe to allow less than 
3/6 of the displacement, although a newly 
packed pump may , 

show much less. j_^;3tz 



^ 



i^ 



3 CI 



1-^ 



^ 



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Fig. 13-1. Method of making step-ups 
using Webster Series 20 Lift Fittings. 
Pipes between lifts must grade down- 
ward in direction of arrows 



^ 



Systems in which the pressiu-e throughout the 
supply lines and radiation as well as in the re- 
turns is normally less than that of the atmos- 
phere are subject to invisible inleakage of air 
around the valves and fittings. Such systems 
require increased displacement also, because of 
the greater volume of elastic fluids due to low terminal pressme necessary 
for circulation. 

Cooling and consequent reduction in volume of the elastic fluids in 
the return present an element of considerable magnitude and uncertainty. 

Well-insulated return pipes, also large volumes of condensation entering 
the main return close to the vacuum pump, require greater displacement 
than would the same radiation with returns in which a considerable portion 
of the vapors could condense between the radiation and the pump. 

Clearance reduces effective displacement in all pumps. The clearance 
for a given cylinder diameter in reciprocating pumps of some makes is ap- 
proximately the same in short-stroke as in long-stroke pumps. Commercial 
sizes of reciprocating vacuum pumps vary in ratio of bore to stroke between 
1 to ^ and 1 to 2 ; it follows that a pump of the latter proportion has greater 
efficiency per displacement than the short-stroke pump because of smaller 
percentage of clearance. 

Experience with reciprocating steam-driven vacuum pumps indicates 
that for most favorable conditions the use of water cyhnders of less dis- 
placement than eight times the normal volume of water of condensation is 
seldom safe. With radiation divided into small units, a ratio of at least 
10 to 1 will be required. 

Ratings for the rotating combination units should be based substan- 
tially on a 10 to 1 ratio of the combined displacement of water and air cylin- 
ders, the ratio of these cyhnders to each other being about 2 of water dis- 
placement to 8 of air. In these pumps the displacement of water must be 
high on account of the constant speed, while a lower proportion of air dis- 
placement may be taken because of the high efficiency of the air chamber 
as compared with reciprocating pump cyhnders which have greater clearance. 
The speed and displacement in rotating pumps Eire normally constant, 
unless expensive variable speed motors are used, whereas in reciprocating 

139 



steam-driven pumps piston speed may be varied through wide range. 
The temptation to gain displacement by excessive piston speed without 
regard to the consequent racking of the pump because of too frequent 
starting and stopping of pistons and valves, should be avoided by adhering 
to a definite relation between piston speed and length of stroke. This 
relation as used for the calculation of basic ratings expressed in column 2, 
Table 13-1 is that the permissible piston speed in feet per minute equals 
20 times the square root of the stroke in inches. These ratings are calcu- 
lated for pumps having equal stroke and bore but they may be assigned to 
other pumps as will be explained later. The relation between the volume 
of the cylinder and that of the water discharged per stroke is figured as 
ten to one. Slip is assumed to be one-sixth of the total stroke. 

The following example will fully explain the method of calculations 
for column 2. 

Selecting from column 1, a pump having 4-in. stroke and 4-in. bore, 
the area of its cylinder is 4 x 4 x 0.7854 = 12.568 sq. in., or 0.0873 sq. ft. 

The piston speed is 20 x V 4 = 40 ft. per min., or 2400 ft. per hr. 

The gross displacement is therefore 0.0873 x 2400 = 209.52 cu. ft. per 
hr.,ofwhichthegrosswaterdisplacement is one-tenth, or 20.95 cu. ft. per hr. 

Since the condensation will weigh 60 lb. per cu. ft. at about 200 deg. 
fahr., the gross water displacement may be expressed as 20.95 x 60 = 1257 
lb. per hr. This must be reduced one-sixth because of slip, or to 1047 lb. 
of condensation per hr. as a basic rating for this pump. 

Taking the average B.t.u. per pound of condensation as 970, the basic 
rating for the same pump may also be expressed as 1,015,600 B.t.u. per hr. 

Ratings for vacuum pumps are properly expressed only in terms of 
pounds of water condensed by the heating system in a given period of time, 
or the equivalent latent heat in B.t.u. given up by the steam while con- 
densing. Ratings in terms of "square feet of direct radiation" are not 
strictly correct and may be misleading since there is not recognition of 
steam pressures, temperature difference, and other factors entering the 
problem. However, for convenient use, factors are shown at the lower left 
of Table 13-1 for reduction of square feet of various types of radiation to 
pounds of condensation per hour which will give approximate results. 

Since many vacuum pumps may have unequal stroke and bore, the 
capacity factors in column 12 are provided to show the relative effective- 
ness of such pumps as compared with "square" pumps having same bore 
and equal stroke. Column 11 shows relative proportions of "unequal" 
pumps in terms of stroke divided by bore. The corresponding factor for a 
pump of any selected relation of stroke to bore is found directly across in 
column 12. 

These factors provide means for selection of stock size pumps where 
the rate of condensation to be handled is intermediate between basic rates 
for "square" pumps stated in column 2. 

For instance, assume a condensation rate of 15,000 lb. per hr. To find 
the proper size of pump, select the diameter of bore in column 1 correspond- 
ing to the basic rate in column 2 nearest equal to the required rate. This 

140 



basic rate is 16,300 lb. per hr. and the bore is 12-in. Then find the factor 
in column 12 equal to the quotient of required rate divided by the basic 
rate for the 12-in. pump. This quotient is 0.92 and the nearest equivalent 
factor in column 12 is 0.91. The corresponding figure in column 11 is 0.80 
which is the decimal relation of stroke divided by bore. 

Multiply the bore (12-in.) by the factor (0.80) and it is found that the 
stroke should be 9.6-in. The nearest equivalent stock size of pump has 
10-in. stroke and therefore a 12-in. x 10-in. pump is selected. 

Where the result of such a calculation does not fit obtainable stock 
sizes, select a stock pump of some other diameter and stroke which, when 
factored by use of column 12, will give a rating at least equal to that required. 

Another problem is that of finding the basic rating for any given pump 
of unequal stroke and bore; for instance, one having 4-in. bore and 6-in. 
stroke. 

The relation of stroke to bore is 6 divided by 4 or 1.5. Finding the 
number 1.5 in column 11 it is noted that the corresponding factor in column 
12 is 1.19. Multiplying 1.19 by 1047, which is the basic rating for a 4-in. 
X 4-in. pump from column 2, the product gives 1246 lb. of condensation 
per hr. as the basic rating for this 4-in. x 6-in. pump. 

It is to be specially noted that the basic ratings shown in column 2 
are calculated and shown for the standard conditions of operation stated in 
the upper right of the table. Other actual or expected conditions of opera- 
tion can be transformed to terms of standard. Where the B.t.u. to be 
emitted are individually calculated for each group of like class and size of 
radiation, these quantities may be multiplied by the factors in column 13 
or divided by those in column 14. The sum of these factored quantities will be 
the basic rating (column 2) from which the size of water cylinder is selected. 

Under conditions requiring lift points in the return; or where there is 
inleakage around inlet valves or elsewhere; or where large volumes of high 
temperature returns enter near the pump ; or if the run of piping from source 
of steam supply to farthest radiator is long ; or where the radiator traps leak 
steam; additional factors must be applied to insure the proper size of pump. 
These factors cannot be summarized since their selection is entirely a matter 
of judgment and of experience with similar conditions. 

Column 4 shows the minimum size for return main entering pump. 
These sizes are based upon a grade in the piping of 1 ft. in 300 toward the 
pump and upon a condition where the return pipe is half-full of water and 
will then discharge condensation by gravity at rates not less than the basic 
rates in column 2. For these calculations, the Chezy formula Q = a c V r s 
is used, in which Q is the quantity discharged, a is the cross-sectional area 
of the pipe, r is the hydraulic radius, s is the hydraulic slope of the pipe 
and c is a coefficient. 

The size of returns inlet from column 4 will also determine the size of 
suction strainer which is to be used in this main at the pump. 

Column 5 is calculated from the same formula to determine the mini- 
mum size of pump discharge and delivery pipe from pump to air-separating 
tank. In this case the pipe is considered to be half-full of water and its 
grade is 1 in. in 20 ft. 

141 



For purposes of determining the proper size of air separating tank to 
apply for a given rate of condensation discharge from pump, the assumption 
is made from field experiences that 1 sq. ft. of liberating surface should be 
provided under average conditions for each 2100 lb. of water discharged 
per hoiu*. Column 6 of Table 1 shows the number of square feet of liberat- 
ing surface required for the basic discharge ratings in column 2. 

Where the tank is used only for air-separating purposes such as plain 
tanks and hydro-pneumatic tanks, the sizes of tanks may be designed 
directly from the figures in column 6. Dimensions of tanks following this 
design are shown in columns 7 and 8. 

In cases where the tank is used for storage of retiu-ns, the tank should 
be larger than that required for piu-poses of air-separation only. Columns 
9 and 10 show dimensions of such tanks based upon storing the quantities 
of water which will be discharged during five minutes at the basic hourly 
rates shown in column 2. 

As an example of the complete calculations for sizing the water end of 
a vacuum pump and for selecting size of auxihary equipment, assume a 
group of three buildings, A, B and C, from which condensation flows at 
rates of 7500, 5000 and 3000 lb. per hr. respectively. 

Also assume that the 7500 lb. per hr. of condensation in building A is 
from blast coils and a closed heater; that the 5000 lb. per hr. from building 
B is from pipe coils, each containing 130 sq. ft.; that the 3500 lb. per hr. 
from building C is from direct radiators in 50 sq. ft. units; that return 
mains are exposed ; and that it is proposed to use a plain type of air sepa- 
rating tank. 

These condensation rates must be transformed to those which would 
be reahzed under the standard conditions upon which this table is based, by 
means of the factors in column 13, using 0.66 for blower stacks and closed 
heater, 0.70 for coils larger than 120 sq. ft. and 0.84 for radiator units of 
50 sq. ft. By applying these factors the equivalent condensation rates are 
found to be 4950, 3500 and 2940 lb. per hr. for building A, B and C re- 
spectively or 11,390 lb. per hr. for the transformed equivalent total rate. 

From column 2, the nearest basic rate is 10,350 lb. per hr. and from 
column 1, the corresponding diameter of bore for this pump is 10-in. 

By dividing the required rate 11,390 by the basic rate 10,350, the 
capacity factor is found to be 1.10. Going into the table it is found that 
1.10 in column 12 corresponds with a relation of stroke to bore of 1.25 
(column 11). Multiplying 1.25 by 10 in. (the bore) gives 12.5 in. as the 
required stroke. The nearest stock size is 12-in. stroke so that a pump 
having 10-in. bore by 12-in. stroke is selected. 

From columns 4 and 5, the minimum requirements for size of retm-ns 
inlet and discharge for this pump are found to be 4 in. and 2^/2 in. respec- 
tively. If the return main is long, it is better to select 5-in. as the minimm 
size of return inlet, since 43 2-in. is not a regular stock size for pipe and 
fittings. The suction strainer will be the same size as the return main 
entering the pump. 

Selecting from columns 7 and 8, the size of plain air-separating tank is 
18-in. diameter by 48-in. length. 

142 



Proportioning of Steam Ends of Reciprocating Vacuum Pumps: 
In proportioning the steam cylinder, the following is a safe rule to use. 
The area of the steam cylinder in square inches times one-third the boiler pres- 
sure should equal the water piston area in square inches, multiplied by the 
combined pressure on the water end {vacuum plus discharge pressure) expressed 
in pounds per square inch. This is given by the following equation : 



A3 X I" = A„ X 



G-^O 



From which we have 



A. X (X+P,)x3 
-'^s = — {Formula 13-1) 

in which 

As = area of steam piston in square inches. 

A^ = area of water piston in square inches. 

Pb = boiler pressure in pounds per square inch. 

Pd = discharge pressure in pounds per square inch. 

V = vacuum at pump expressed in inches of mercury. 

V 

-7)-= approximate vacuum in pounds per square inch (2 in. mercury = 

approximately 1 lb. per sq. in.) 

Note: All pressures are by gauge. 

In the above formula, the working pressure is taken as one-third of 
the boiler pressure, in order to allow for the low mechanical efficiency of 
the pump, as well as for the inevitable drop in steam pressure between the 
boiler and the inlet of the pump. Carelessness in setting up the packing 
in the water-and-air piston is prevalent and to be expected. It is also 
necessary for the pump to keep going even when the boiler pressure may 
be considerably lower than the normal working pressure. 

While in some cases this formula may give dimensions which appear 
to be larger than necessary, it is seldom safe to make the area of the steam 
cylinder less than twice the area of the water-and-air cylinder. 

Column 3 of Table 13-1 shows sizes of steam supply and of vacuum 
governor, for boiler pressure of 75 to 125 lb. per sq. in. 

Power-driven Reciprocating Vacuum Pumps: Lack of available 
steam pressure to operate the piston in reciprocating vacuum pumps requires 
that some other source of power must occasionally be utilized. Where this 
is the case, a reciprocating pump is in many cases unsuitable because of the 
difficulty in handling the varying load during each stroke and because no 
satisfactory means for controlling the displacement to maintain the desired 
degree of vacuum has yet been devised for this type of pump. 

To move the reciprocating piston in the water cylinder by means of a 
connecting rod and crank, the latter necessarily rotating at low speed, 
entails gearing or an extremely large pulley and countershafting. Inasmuch 
as the torque varies from almost nothing at the ends of the stroke to a high 
maximum at about three-fourths stroke, back-lash, noise and wear of gears 

143 



or slapping and slip of belts are to be expected unless a heavy fly-wheel is 
used, and in any instance the power consumption is excessive. 

Variable-speed motors are sometimes utilized for driving, but are 
expensive, and give only two or three steps of displacement, which must be 
selected either manually or by complicated delicate electrical controllers. 

There is nothing to commend in intermittent control. Constant speed 
and displacement with a vacuum breaker to admit air when the load is 
below normal is probably nearest to a satisfactory arrangement where 
power-driven reciprocating vacuum pumps are used. 

Disposal of Vacuum Pump Discharge : Conditions vary to such an 
extent that good judgment is the only safe guide in determining the best 
method for the disposal of the vacuum pump discharge. In no case should 
the head against the discharge of reciprocating pumps exceed 15 lb. 
unless the pump stroke materially exceeds the bore and thus reduces the 
bad effect of clearance. Usually one of these seven methods will best apply : 

1. Discharge to Waste: Disposal by discharge to waste involves loss of 
all the valuable heat and water, but in rare cases this is permissible. 

2. Discharge through Air-separating Tanks: Where first thought seems 
to suggest disposal to waste, it will in many cases be found possible to 
deliver the water and air into a separating tank, or stand pipe sufficiently 
elevated for the water, after separation, to flow by gravity to some point of 



iT^,^ Steam to 
Vacuum Pump 

Globe Valve 




WEBSTER LIFT FITTING 

Fig. 13-2. Method of connecting vacuum pump to a plain receiving tank 



144 



valuable use, such as boiler or feed-water heater, etc., or for hot water supply. 

Where, due to structural conditions, a suitable elevated location cannot 
be found, the effect of head may be obtained by use of a hydro-pneumatic 
tank as described under heading No. 4. 

3. Discharge to Open Vent Tanks: Open vent tanks, otherwise called 
plain separating tanks, normally serve the purpose of releasing the entrained 
air from the discharge of the vacuum pump. (See Figure 13-2.) 

This air removal requires the generous water surface area of either a 
tank of large horizontal cross-section, rather than one of large vertical 
sectional area, or a tank with a large vertical head and enough sectional 
area to permit of low-velocity downward water flow while entrained air is 
floating to the surface against the water current, as in a stand pipe. For 
removal of air, one square foot of horizontal cross-section has usually been 
found sufficient for each 2100 lb. of water per hour. A stand pipe, with 
diameter equal to that of the pump cylinder, is usually sufficient, although 
a more logical rule is to make the cross-sectional area of the stand pipe 



Water Control Valve. 
Cold Water Connection. 



Overflow to Waste 



Discharge from 
Vacuum Pump 



Multiply maximum back pressure 
carrieU in heater by 3 to determine 
least dimension in feet 




Fig. 13-3. Typical application of Webster Water-control Receiving Tank in connection with an open feed- 
water heater. The heater should be set on a foundation of sufficient height (a vertical rise of not less than 
three feet) between the pump outlet of the heater and the suction valves of the boiler-feed pump 

145 



bear some direct relation to the amount of condensation from which the air 
is to be separated, and to the height of column of water through which the 
air bubbles must rise against the flow of liquid. 

The fact that the discharge of reciprocating wet-vacuum pumps is a 
mixture of water and air favors the use of a freely vented separating tank 
wherever a suitable location may be obtained. This is such height that 
the pressure produced by the water column will be sufficient to overcome 
that in the low-pressure boiler, feed-water heater (see Figure 13-3), or 
other point of disposition. 

The effective column or head between the pump-discharge valve and 
the inlet of the separating tank will be less than that of solid water by the 
volume of air contained in the mixture. The contents in separating tank 
and discharge pipe therefrom will be water only. It is, therefore, possible 
with pump discharge properly proportioned and provided with lift fittings, 
vertical rise pipe to tank, etc., to obtain a gravity head in the tank discharge 
above the level of the pump valve deck, considerably greater than the pres- 



Vent lo Atmosphere 



Automatic Air Vent Valve 



Automatic Water Reliei 
Valve and Overflow 



To Drain unobstructetS. 
Funnel--'' 




Return to Boiler- 



Gate Valve 

V 



Check Valve ^ Valve- 

Dy-Pass to Sewer-- 



Connection from Low Pressure 
Steam Main to Steam Gauge 



JHGIobe Valve 

WEBSTER 
COMBINATION GAUGES 



WEBSTER 
TRAP 




WEBSTER 
SUCTION STRAINER 
SYLPHON V 



-Vacuum Pump Discharge 




Motor 



WEBSTER LIFT FITTINGS 

Fig. 13-4. Method of connecting geared-type vacuum pump and 
Webster Single-control Hydro-pneumatic Tank 

146 



sure in the pump cylinder necessary to lift the valves and discharge the con- 
densation to the elevated return tank. 

4. Discharge to Hydro-pneumatic Tanks: As the name indicates, hydro- 
pneumatic tanks bring the elastic pressure of the liberated air to act on 
and supplement the head, in the discharge of the water of condensation. 
A float-controlled valve is placed on the air outlet of the separating tank, 
and so arranged that when the water of condensation has not sufficient 
head to flow by gravity to the point of use, the air will be confined in upper 
part of tank. As the pump continues to deliver water and air to the tank 
(see Figure 13-4) the pressure inside the tank increases until sufficient to 
discharge the water, thus lowering the water line and eventually permitting 
escape of the surplus air through the float-controUed air valve. 

The discharge of condensation to low-pressure boilers, in which the pres- 
sure may at times be less than that of the atmosphere, requires another 
float in the hydro-pneumatic tank (see Figure 13-5) to control the valve 
on the tank water discharge and keep this pipe closed at such times as there 
might be danger of air flowing from the tank to the boiler. 

The hydro-pneumatic type of tank is used only where an open tank 
cannot be located at a height sufficient to provide gravity head to discharge 
the tank contents against the maximum pressure in the heater or boiler, or 



Vent to Atmosphere 



Automatic Air Vent Valve 

l- 



Automatic Water Relief 
Valve and Overflow 



To Drain unobstructed" 




Equalizing Line connect to 

Boiler at Point having no 

Steam Flow ■ 



WEBSTER 
BOILER FEEDER 



High Water Line 
of Boiler . | 2" 

Center Line of , 

Boiler Feeder' 

To Boiler 



^To other Boiler 



Floor LinCx 



^Connection from Low 

Pressure Steam Main 

to Steam Gaug 



"Pump Discharge 




WEBSTER 
^HYDRO-PNEUMATIC TANK 



Motor 



Check Valve-p^gjj^^jjgg^g^ "-WEBSTER SUCTION STRAINER 
Fig. 13-5. Typical connections to vacuum pump, double-control hydro-pneumatic tank and boiler feeder 

147 



where there are large variations between the maximum and minimum pres- 
sures to be overcome. Where the hydro-pneumatic tank is used merely as 
a substitute for an open separating tank, little advantage may be taken of 
the light density of the pump discharge. 

The confined air pressure in the hydro-pneumatic tank plus the gravity 
head in the tank discharge pipe must be sufficient to cause flow to the place 
of disposition. This confined air pressure plus the column of mixed air and 
water in the pump discharge to the tank is the total head against which 
the pump must act. 

Where pressure on the heater, boiler, etc., varies materially from time 
to time, but in general is near the minimum, a substantial saving in energy 
may be obtained by using a hydro-pneumatic tank instead of a plain tank 
set at higher elevation to overcome the peak pressure in the boiler or heater. 
The use of a plain tank under these conditions keeps the pump operating 
constantly against the maximum head, where a hydro-pneumatic tank set 
lower operates as a plain tank whenever the gravity head in the tank is 
sufficient to cause flow at the low elevation, and employs the combination 
of air pressure and gravity head (with air vent closed) only at times of peak 
load. Only then is the air pressure load added to the pump discharge. 

5. Discharge to Loop Seal on Tank Outlet to Heater or Boiler: The dis- 
posal of water of condensation from a return tank to a feed heater (see 
Figure 13-3), boiler or other receptacle, in which there may be greater pres- 
sure than that of the atmosphere, requires guarding against back flow of 
steam, air or whatever other elastic fluid may be present at the outlet. 

A loop seal has been found most suitable for this purpose, provided the 
seal is made long and contains ample volume in the vertical leg on the 
pressure side. A variable pressure when increasing tends to force the level 
of water down in the leg on the pressure side and up in the leg toward the 
tank. If there is not sufficient water in the loop, the water will become 
displaced, and the seal broken before enough of a water column has been 
built up in the leg from the tank. The column will then blow into the return 
tank and the steam or other elastic fluid will continue to blow while its 
pressure is above that at the tank outlet. 

The fact that water in the tank is ready to seal the loop below will 
not avail as long as there is a difference in pressure between the tank and 
boiler sufficient to blow a comparatively short slug of water back into tank. 
The only way to restore the seal is first to equalize the pressure on both 
legs. A good practice is to proportion the leg on the pressure side to hold 
twice the contents of the pipe from the tank to the bottom of the seal. 

6. Discharge to Receiver and Boiler-feed or Tank Pump: Where the head 
on the delivery side of steam-driven vacuum pumps exceeds 15 lb., it 
is good practice to deliver the condensation to a vented receiver (see Figure 
13-6) located close to the level of the vacuum-pump outlet. This receiver 
should be connected to a separate steam or power-driven water pump which 
is capable of delivering against the maximum head. (See Figure 13-7.) If this 
pump is steam-driven, its displacement should be controfled by a throttle 
valve, actuated by the water line in the receiving tank; if power-driven, the 
effective displacement may best be controlled by bypass valve between 

148 



^.^Discharge from Vacuum Pump 




Boiler Feed Pump 
and Receiver 



Drain to Sewer 
Check Valve 



V»EBSTER LIFT FITTING 
I'ig. 13-6. Method of connecting vacuum pump and Hutomatic boiler-feed pump and receiver 



Vent to Atmosptiere 
Run to Air above Roof 




WEBSTER LIFT FITTING^ To Sewer WEBSTER SUCTION STRAINER 



Fig. 13-7. Method of connecting vacuum pump, boiler-feed pump,a^d 
Webster Steam-control Receiving Tank 

149 



pump suction and delivery, and actuated by water-line float in the receiver. 

7. Dry-vacuum Pump Receiver and Water Pump: This combination 

proves very effective under conditions of high delivery head where the main 



Globe Valve 



Globe 
Valve 



Lubricator 




Fig. 13-8. Method of making connections to steam-operated vacuum pump 

return can be arranged to flow by gravity to a closed receiver, which in turn 
is sufficiently elevated above the location of water pump to provide a head 
of 2 to 3 lb. on the pump inlet valves. 

The dry-vacuum pump being free from dirt and abrasive material, may 
have close clearance and fairly high efficiency. It may be located above 
and take its suction from the top of the receiver, and frequently some form 
of condenser may be arranged in the suction line to absorb and utilize other- 
wise wasted heat from the air and water vapor and at same time materially 
reduce the volume of vapor to be handled. 

The receiver, if properly designed, forms a receptacle for the grit and 
impurities which would otherwise injure the water pump; and it also affords 
space for a float governor for controlUng the water pump by the varying 
volume of return water. 

Excessive vacuum in the receiver will cause trouble in the water pump. 
For this reason, a vacuum governor should always be used to control the 
dry-vacuum pump and to hold the vacuum within pre-determined limits. 

ISO 



Suction Strainers : The worst of the grit and |^,,^ j,^^^ ,^^^ 
dirt from condensation should be retarded and re- ^"'^^ 
moved before entering the pump where it would 
score the water cylinder. Strainers (see Figure 
13-8) with readily removed baskets for use on the 
main vacuum return line were first designed and 
recommended by Warren Webster & Company 24 
years ago. The original Webster design with little 
modification has been almost universally adopted. 

In some instances, conditions arise where large 
quantities of returns, at unusually high tempera- 
tures, are discharged into the line near the vacuum 
pump. These may come from special 
apparatus such as cooking or hospital webster '~^W~ ' 

fixtures, dry kilns, or other devices vicuum governor-^ 
using high pressure steam. A combi- . 

.' n ,- , • 1 1 V* Vacuum Line 10 Vacuum 

nation oi suction strainer and a cook- Gauge and suction strainer 
ing device, shown on page 262, wiU be £=sai=^Ji[HlP=l 




Globe Valve Union 



Plug 



f 



found to be of advantage, particularly 
where it is desired to carry a high 
vacuum at the pump. Cold water, 
passing through copper coils, is used 
to condense the vapor in the main re- 



turn. 

Vacuum Governors: In steam- 
driven pumps, control of displacement 
by the degree of vacuum maintained in 
the return line may be effectually ac- 
complished by tlirottling the steam 
supply. (See Figure 13-9.) Simple 
forms of diaphragm-actuated throttle Fig. 13-9. 
valves will control the degree of 
vacuum in the main return within sufficiently narrow limits for all practical 
purposes. 




Connections for a Webster Vacuum- 
pump Governor 



151 




152 



CHAPTER XIV 

Laboratory Tests of Return Traps 

THE object of laboratory tests of appliances is to determine the efficiency 
of the apparatus tested, as a guide to judgment in selecting materials 

or in the case of technical schools, as a part of the instruction of the 
students in methods of scientific research. 

All of the operating conditions possible or probable in an actual heating 
system cannot be artificially produced in the laboratory, nor is it practical 
to carry out tests long enough or upon sufficient numbers of samples to learn 
all facts which become evident in practice. Furthermore, as the whole 
heating system, including design and installation, has its effect upon the 
efficiency of the devices entering into it as parts, any laboratory tests for 
efficiency can indicate only the results which are probable when the devices 
are properly used in practice. 

Too much stress should not be laid, therefore, upon the comparative 
performances of any two makes of traps during laboratory tests. Knowl- 
edge of performances in actual installations of many heating systems, 
maker's ability and care in manufacturing, shop tests, inspection and proper 
engineering application of the traps are of great importance to the investi- 
gator who wishes to make commercial use of his study of such devices. 

However, as laboratory tests have their useful place in commercial 
investigation, the various types of traps and the results of tests which may 
be expected are outlined in this chapter. Mention is made of many com- 
mon forms of tests which give erroneous results so that these errors may 
be avoided. Methods and apparatus for reliable tests are mentioned and 
illustrated. 

Usually the object of a laboratory test of a return trap is to determine 
one or all of the following characteristics: 

1. Effect of the trap upon radiator efficiency. 

2. Efficiency of the trap for the removal of air and water of condensation 
and for conservation of steam and vapor. 

3. Behavior of the trap without special adjustment to meet the varying 
conditions of pressure and vacuum in normal practice. 

4. Durabihty of the trap through a long period of use. 

5. Construction features of the trap, particularly the amount of valve 
movement, which indicates the ability to get rid of dirt and pipe scale. 

The results of tests by many investigators, of radiator and trap effi- 
ciency, have varied widely and have often been misleading, largely because 
the methods of testing have been faulty and partly because the devices 
themselves have not always been manufactured to operate uniformly. 

Most tests of which the results have been published have been faulty 
through failure to cover a wide enough variety of test conditions, tlirough 
limitation of the time period for each test to a few minutes instead of hours, 
and through considering and testing only one or two samples of any one 

153 



device, instead of six or more selected by the investigator from the manu- 
facturer's stock bins or purchased in the open market. 

Tests for Heating Efficiency: The heating efficiency of a radiator 
depends upon physical conditions within the radiator which are affected by 
the action of the return trap. The radiator, among a number of common 
size and type, which maintains the highest average temperature when 
tested under the same conditions, is the most efficient. 

The greatest possible steam economy is obtained where this efficiency 
is liighest; that is, where steam is being condensed to the greatest extent 
possible within the radiator and the trap passes the least amount of steam or 
vapor into the return pipe. 

The highest radiator efficiency can be obtained only where the dis- 
charge is sufficiently and properly restricted to prevent steam from blowing 
into the return. Also the air released from the steam in the radiator must 
be allowed to settle to the lower parts, from which it can enter the trap and 
be discharged. 

A return trap, in addition to restricting the discharge, must effectively 
accomplish the following: 

1. The discharge of aU water of condensation as formed. Otherwise 
water accumulates in the radiator, prevents free discharge of air and thus 
reduces the amount of surface effective for emitting heat from the steam. 

2. The discharge of all air and other gases from the radiator im- 
mediately upon their reaching the discharge outlet. 

3. Thorough prevention of the discharge of steam to the return. 

To accomplish these requirements the valve of a return trap must 
open or close within a very narrow range of temperature, above or below 
that of steam at pressure, irrespective of variations in steam pressure, 
and must adapt itself to such changes of pressure and corresponding steam 
temperature as may be met in practice. 

A brief review of the various types of return traps will facilitate a 
better understanding of tests and the results which are desired. 

AU return traps commonly used in low-pressure or vacuum steam heat- 
ing practice may be classed as float, differential, and thermostatic traps. 

Float traps may have sealed floats, Figure 
14-2, or inverted open buckets as the means of 
operation. In either case, the float is raised 
by incoming condensation to uncover the valve 
seat through wliich water is discharged. Air 
escapes into the return pipe through an air 
port, which must be located above the highest 
water level in the trap. The air port is con- 
trolled in some makes by thermostatic devices 
to prevent leakage of steam to the return. 

Tests upon a float trap may generally be 
expected to show considerable leakage of steam 
to the return unless the air port is thermo- 
statically controlled. If the air port is so 

154 




t 



Fig. 1^2 Float trap with sealed float 



controlled, the small port and its mechanism may be vulnerable to the effects 
of dirt and rust. Such traps, however, will be found to have large water 
discharge capacities and some of the various makes can be used to advan- 
tage where widely varying volumes of water must be discharged without 
respect to temperature. 

A differential trap depends for operation upon the difference in pres- 
sure at the inlet and at the outlet. In its simplest form, it is a check valve 
which is closed when the difference in the pressures ahead and back of the 
clapper is insufficient to overcome the weight of the clapper, Inasmuch as 
no special means are provided for discharge of air, such a valve may be ex- 
pected to leak steam to the return under any conditions of higher differential 
pressure, and to stay closed with consequent 
air binding and water logging of the radia- 
tion when the pressure differential falls 
below the predetermined limit for which the 
valve is adjusted. 

Another form of differential trap is 
shown in Figure 14-3. Water entering the 
valve body raises the float, thus closing the 
air port by means of the valve piece attached 
to it. A liigher pressure in the lower part 
of the trap B than that existing in the 
chamber A results in the operation of the 
piston which raises the valve from its seat 
by means of the connecting valve stem. As 
the condensation is discharged, the water 
level lowers and causes the float to faU, thus 
uncovering the air port, and equalizing the pressures on opposite sides of 
the piston. The weight of the operating parts and the force of the spring 
then closes the valve. Tliis trap may be expected to show fairly good 
results in laboratory tests but it is not satisfactory under the usual operating 
conditions in which dirt and scale are always present. 

A thermostatic trap depends for its operation upon the difference be- 
tween the temperature of steam at the pressure in radiator, and the tempera- 
ture of the condensate or air to which the thermostatic member is exposed. 

Many devices have been made which depend upon the expansion and 
contraction of metals or composition, or which make use of a bourdon tube. 
As a class these have failed because there is not enough difference in area 
between the inside and outside of the spring to produce the required force 
at normal difference in temperature between steam and air vapor at a given 
exterior pressure. This and other faults, such as the necessity for adjustment 
for varying pressure conditions and slowness in operation, have Jed to the 
abandonment of these types by most manufacturers. 

Of all types of return traps, the ones in general use today are those 
which depend for movement of the valve piece upon the change of vapor 
pressure of fluids confined within a flexible chamber when subjected to dif- 
ferent exterior pressures and temperatures. The volatile fluids contained in 
the flexible chamber vaporize to a greater or less pressure depending upon the 

l.-)5 




Fig. 14-3. Differential trap 
with float and piston 



high 
con- 



temperature of the steam, vapor, water or air wliich surround the chamber. 
The expansion or contraction of the chamber moves the valve piece which 
is attaclied to the free end of the chamber. 

These traps are, generally speaking, of either the "inboard" type where 
the thermostatic mernber is exposed to the temperature and pressure of the 
steam, water and air as it exists at the radiator outlet, or of the "outboard" 
type which depends for operation upon the conditions existing between the 
valve piece and the entrance to the return piping beyond the trap. 

To be effective for the inboard type, the thermostatic member must 
expand and contract through a distance sufficient to open and close the 
valve under the influence of the extremely small differences of temperature 
which exist during normal operation. Most traps of the inboard type are 
inefficient because of the very short "stroke" which can be realized with the 
inelastic disc construction generally utilized for the flexible chamber, this 
defect resulting in inability of the trap to rid itself of dirt and scale. 

Traps of the outboard type are affected by the pressure and temperature 
of the return. They are in proper adjustment only at one definite pressure 
and temperature and out of adjustment at all other normal combinations of 
pressure and temperature. They cannot be adjusted even for these normal 
variations in radiator pressures and vacuum in the retur^i, and as a result 
usually water-log and air-bind the radiator by staying closed when 
temperature and pressure exist, or stay open and blow steam under 

ditions of low temperature and pressure. 

The trap shown in Figure 14-4 is a ther- 
mostatic trap of the inboard type and as such is 
affected in operation only by the temperature 
and pressures existing within the radiator. The 
multifold design of the thermostatic member gives 
it great elasticity and consequent ample move- 
ment in response to change of temperature and 
pressure in the medium surrounding it. This 
member contains liquid which makes the trap 
self-compensating for difference in operating 
pressures of steam within the radiator. Its con- 
struction, with conical valve piece seating on 
sharp-edged seat, assures positive self-cleaning. 
Dirt and scale cannot lodge between valve and 
seat and permit steam to leak into the return. 
It has been stated that a trap must not leak steam to the return, but 
in this connection there should be no confusion between steam discharged 
through a trap and vapor rising from hot condensate. Though their ap- 
pearance during certain forms of visual tests are much alike, they are two 
entirely different things, and if confused with each other, as is sometimes 
done, wrong conclusions will result. 

Many times, highly efficient radiator traps are condemned for leaking 
steam, due to the observed vapor of re-evaporation noted at their discharge 
outlet, and less efficient traps have been commended because of absence of 
such vapors. 

156 




•'S 



14-1. The Webster 
Sylphon Trap 




100 



Fig. 14-5. Re-evaporation chart for determining the percentage of water re-evaporated from any tem- 
perature between 300 and 170 deg. fahr. into water vapor of a lower temperature and corresponding pressure 



157 



The absence of vapor at the discharge is in reality an indication that the 
trap is holding back condensation and entrained air until the temperature 
of the discharge is materially less than that of steam at the pressure of the 
outlet. The consequence of such holding back is a partially air-bound and 
water-logged radiator, with less than full radiating efficiency. 

Visibihty is deceptive. A great amount of moisture in the atmosphere 
and favorable light conditions both add to the visibility. The air dis- 
charged from an efficient trap is saturated with water at discharge tempera- 
ture and this water mixing with air at room temperature looks like steam, 
while the discharge of a trap utterly deficient in air removal shows only the 
vapor of re-evaporation. 

The water of condensation contains total heat in excess of that in water 
of condensation at lower pressure. This excess heat boils off some of the 
condensation into steam. The amount so boiled off is entirely dependent 
on excess of total heat in outflowing condensate above total heat of water 
at lower pressure. 

If steam passes out with condensate, a steam of greater total heat is 
dissipated. A fuUy efficient trap releases the condensation at or near steam 
temperature and radiator pressure, into a return of lower pressure. All 
heat above that consistent with lower pressure then generates vapor. This 
vapor passes to the vapor receiver in a test. A certain amount of vapor 
per pound of condensation is normal and any excess of vapor above the 
normal is steam leakage. 

The condensate from a higher pressure into a lower pressure wiU never 
be at a higher temperature than that due to steam at the lower pressure. 
The excess of the heat in the outflowing condensate will flash part of the 
water into steam. 

These points are emphasized to show the falhbility of visibility test to 
show the efficiency of return traps. 

Very rough tests are often made by connecting a trap to the end of a 
pipe or to outlets in a header to which steam is admitted at the pressure 
usually used, the trap discharging into the atmosphere. A test of this kind 
merely shows whether the trap shuts off. 

Comparative values are sometimes placed upon traps by considering 
the quantity of water discharged during equal periods of time. The traps 
are successively attached to the same test radiator, the condensate is care- 
fully weighed and the conclusion drawn that the trap passing the largest 
quantity in a given time is the best. It is evident that such a test shows 
merely the condensing rate of the radiator under the room temperature 
conditions. Nothing is demonstrated regarding the performance of the trap, 
for it is only when condensation is held back in the radiator that the capacity 
of the trap is exceeded. This test is only a determination of the condensate- 
discharging capacity of the trap. 

The vacuum which can be maintained at the discharge end of a trap is 
occasionally regarded as a criterion of the comparative worth of traps. For 
such tests, the apparatus consists of a radiator, a return trap, a return 
connection to a vacuum pump, and devices for maintaining constant pressure 
of steam supply to the radiator and for operating the pump at a constant 

1S8 



speed. The trap maintaining the highest vacuum during the test is consid- 
ered to be the best. With httle or no attempt to determine the extent to 
which the radiator is air and water bound, such data has frequently led to a 
wrong choice of traps and the results when in actual operation on a heating 
system have proved correspondingly unsatisfactory. 

Another test is to connect a trap to a radiator with discharge to atmos- 
phere, and noting the operation. 

Particularly erroneous conclusions will be reached unless careful 
distinction is made between the vapor which is steam and the vapor which 
is due to re-evaporation. 

Much can be learned as to trap behavior from such a test, yet the 
conditions are often not the same as in actual service operation. The return 
piping connection and the pressur^-'tkereiTr-hwve' consideralyle effect upon 
their operation so that rough tests of this nature should not be accepted as 
conclusive, but as indicative of trap operation. 

These few devices and methods are the ones commonly used for de- 
termining comparative worth of return traps where only the most easily 
procurable testing apparatus is available. Like other scientific investiga- 
tions more careful methods will lead to more reliable results and with proper 
apparatus and thoughtful procedure it is entirely practicable to obtain test 
data which can be relied upon as accurately forecasting the success which 
may be expected from the use of any return trap in an actual heating system. 

The first thought for any reliable test should be to create laboratory 
conditions as nearly as possilDle like those met in actual practice. Coinci- 
dently, the apparatus should be designed to provide exactly like and 
simultaneous test conditions where traps are tested for comparison, and of 
course, appliances for measuring the results must be carefully placed and 
adjusted. Then, by following a proper test, planned to exhaust the various 
possibihties of different operating conditions, results are secured which can 
be accepted as conclusive. 

Enough has been said to show that valuable data regarding the probable 
performance of return traps can be obtained in the laboratory where suitable 
apparatus is available and where suitable test methods are carefully applied. 
However, the long-time test of devices in actual heating systems is the best 
guide for determining the relative value of return traps, and further, the 
efficiency of a good return trap can be fully reahzed only when the heating 
system itself is properly planned and operated. 



159 



Part II. Webster System Specialties 
and Applications* 



CHAPTER XV 

Webster Systems of Steam Heating 

THE title "Webster Systems of Steam Heating" is used to designate 
not only the Webster Specialties which are used in the several types of 
heating systems, but also the methods and arrangements, most of them 
original with the manufacturer, which assure economical and efficient 
operation of the heating plant as a whole. 

In addition this designation embraces a far-reaching policy of co-opera- 
tion — Webster Service — which is rendered through branch offices and service 
centres of the manufacturer in the principal cities. 

This three-fold system of specialties, methods and service is the 
result of continuous development since 1888. 

Many of the methods of application have been reduced to the form of 
Standard Service Details, as shown in Chapter 22 and elsewhere in this book. 

The selection and adoption of a Webster System carries with it the 
assurance to the architect, to the designing engineer, to the heating con- 
tractor and to the owner, that the responsibility is not divided between 
manufacturers of various appliances. 

In a Webster System all of the appliances are co-ordinated in their 
application and function, and the great risk of patchwork selection and 
responsibility is avoided. 

Webster Specialties have been proved by the test of use over many years 
to be the highest quality attainable in design, workmanship and material. 

Webster Service and the standard and special details of recommended 
application are the result of long experience and pioneering in solving the 
practical problems that have arisen. 

Webster Systems are flexible. There is a type or a modification that 
will fit each building. Following the classification in Chapter 10, Webster 
Systems of Steam Heating are divided into two general types: Webster 
Modulation Systems and Webster Vacuum Systems. 

Webster Modulation Systems 

As stated in Chapter 10, the vacuum and modulation types of steam 
heating systems are sufiiciently alike to be classed as one broad type of 
system, in which the circulation of steam is produced by a flow of the heating 



*Drawings showing applications, and dimensions of apparatus are subject to change without notice. 
Certified drawings of apparatus will be furnished upon request. 

161 



medium from a higher to a lower pressure. They are dissimilar in the method 
of disposing of the products of condensation. 

The Modulation System may be sub-divided according to source of 
steam supply, or more particularly type of boiler, into three general classes: 

1. Low-pressure heating boilers operating up to 10-lb. pressure. 

2. Boilers operating at from 10 to 50-lb. pressure. 

3. Street systems, carrying any pressure. 

1. Boilers Operating up to 10-lb. Pressure: A typical arrange- 
ment of the Webster Modulation System as installed in connection with a 
low-pressure heating boiler is shown in Figure 15-1. The initial pressure 
is closely controlled by means of an extremely sensitive Webster Damper 
Regulator. The steam is admitted to each radiator through a Webster 
Modulation Valve which permits modulation of room temperature by simple 
hand manipulation. Condensation is discharged and air is vented from 
each radiator through a Webster Return Trap which maintains full heating 
efficiency of the radiator and eliminates the annoyance, difficulties and 
noises common to ordinary gravity steam heating systems. 

Condensation and air from each radiator flow by gravity through a 
system of return risers and mains into the Webster Modulation Vent Trap, 
where the air is automatically vented, permitting the system under favor- 
able boiler conditions to operate for long periods under partial vacuum or 
"vapor," but also due to the flexibility of the system permitting higher 
pressures to be carried in severe weather when a maximum amount of heat 
is required. Fig. 24-61, Page 268, shows the detail connections of the Modu- 
lation Vent Trap. 

The system of supply and return mains and risers should be sized and 
run as recommended for Modulation Systems in Chapter 11. As a general 
rule, supply mains and risers are not dripped through traps, but directly 
into a wet -return line, the air being vented into the dry-return line which 
is run back above the boiler water line to the Modulation Vent Trap. 

Where building conditions make the running of a wet-return line im- 
possible, the mains and supply risers are dripped and vented through 
Webster Return Traps into the dry -return line. It has however been found 
preferable from practical experience to run a wet-return line wherever 
it is physically possible to do so. 

In view of the general adoption of Webster Modulation Valves and the 
hot -water types of radiators, the top feed supply connections are more 
generally used. When placed in this position, the valves are in a very accessible 
location and it will be found easier to control the temperature of the room 
by operating the valve than by following the customary method of opening 
and closing the window. 

Figure 22-43 on page 228 illustrates the method of di'ipping and venting 
the supply main into the wet return. Figures 22-45 and 22-49 on pages 229 
and 232 show how the basement radiators are connected up to the system. 
Several methods of dripping the risers and mains through Return Traps 
into the dry return are shown in Chapter 22 on pages 215, 216 and 217. 

The Webster Modulation Vent Trap is essentially a part of the Webster 
Modulation System, to be used on installations where the sizes of pipes, 

162 



valves and return traps have been computed in accordance with the methods 
explained in Chapter 11 and also on the basis of pressure differential outlined 
in Chapter 23, and summarized in Table 23-7. 

Where the pressure difference between that in the boiler and that in 
the main return line is likely to exceed the available gravity head between 
the return main and the boiler, the Webster High-duty Vent Trap may be 
required. 

The principal conditions under which the High-duty Vent Trap may 
be employed are as follows: 

1. Where it is of advantage to design the system for a continuous 
operating steam pressure ranging from 2 to 3 lb. to occasionally 10 lb. 

2. In an existing installation, where the pipe sizes are already fixed, 
as for example an old building in which complete steam circulation cannot 
be obtained under 2 or 3 lb. 

3. In a proposed installation where the basis upon which the pipe sizes, 
valves and return traps are figured is either uncertain or unknown. 

4. Under certain operating conditions such as continually changing 
janitor service, operating the boiler without the use of a sensitive low-pressure 
damper regulator or with the damper regulator entirely detached. 

5. In cases where special grades of bituminous coal are burned in 
certain types of boilers, and it is impossible to maintain low steam pressure 
even with careful attention and correct damper regulation. 

2. Boiler Pressure from 10 to 50 Lb.: With this type of system 
the heating medium is generally live steam taken directly from the boiler 
and is reduced to the desired pressure, varying from atmospheric up to 1 or 
2 lb., by means of a pressure-reducing valve. This initial pressure in the 
heating main will vary according to the pressure drop for which the supply 
piping has been sized, and to a certain extent with respect to the outside 
temperature and weather conditions. 

The only exhaust steam available is that from boiler-feed pumps and 
other auxiliaries if steam-driven. The exhaust is utilized after it has been 
made suitable for use by passing through a Webster Oil Separator, drained 
by a Webster Grease Trap. 

The system of supply and return mains and risers should be sized and 
run as recommended for Case 1. 

In small and moderate size buildings the supply mains are usually run 
on the basement ceiling and connected through laterals to up -feed risers 
supplying the radiators. 

In tall buildings and in buildings of certain types it is desirable to avoid 
running the large supply mains on the basement ceilings. Where a building 
is spread over a large area, if the supply main is located on the basement 
ceiling, the pitch required by the main and by the dry return may cause the 
latter to be too low when approaching the point of discharge. In both of 
these cases, what is known as the "overhead" or down-feed system is em- 
ployed, the steam being fed through a main up-feed riser to a distributing 
main located at the ceiling of the top story or preferably in the attic, steam 
being delivered to the various radiators through a series of down-feed risers. 

The drop risers are connected into a wet return or gravity drip fine. 

16.1 



The return risers are joined into an overhead dry-return main, which is 
carried back to the point of discharge. The main supply riser is dripped 
either into the wet return or through a Webster Heavy-duty Trap or suitable 
size return trap into the dry-return main. 

In buildings of only one story, the steam supply line is run along the 
ceiling to feed each radiator through a short down -feed riser which must 
be dripped through a return trap into a dry return. The use of the Webster 
Double-service Valve attached to the radiator as shown in Fig. 24-23, page 
253, performs the two-fold service of supply valve for the radiator and a 
trap for draining the riser. 

For factories, stores, loft buildings, etc., when there are a number of 
radiators heating one large room, Webster Modulation Valves are sometimes 
omitted and ordinary radiator supply valves used instead. Such systems 
are designated as Webster Semi-Modulation Systems to distinguish them 
from the usual type of modulation system. 

In general, for the type of building for which the Webster Modulation 
System is proper, the advantage of using Webster Modulation Valves is so 
evident that they are considered a necessary part of the equipment. 

Radiators may be exposed, concealed under window seats or behind 
grilles, or placed overhead to take care of skylights and unusual roof ex- 
posures, as with vacuum systems. 

The radiators are drained through Webster Return Traps, into a system 
of return risers, and in the same manner. 

Air-valves are unnecessary on the radiators, as the air is relieved through 
the return traps. 

It should be noted, however, that as the actual difference in pressure 
through the supply valve and return trap of a modulation system is less 
than Avith a vacuum system, these valves and traps must not be rated as 
high for modulation as for vacuum system practice. It will therefore be 
observed, from a study of Chapter 11, that it is necessary to deduct the 
pressure drop for which the system is designed from the initial pressure in 
the heating main. With atmospheric pressure in the return piping, this 
difference will represent the differential pressure on which the capacity rating 
of the valves and traps should be based. 

The products of condensation flow by gravity through the system of 
return risers into the basement return main, thence to a hot-well or to the 
receiver of a pump and receiver. If the former, a condensation pump is 
used to discharge the water into the boiler. In the latter case, the pump 
and receiver take care of the liberation of entrained air and return of 
condensation to the boiler. 

The condensation pump, or pump and receiver, will usually be electric- 
ally driven, but if the boiler pressure is 25 or 30-lb. or above, the steam- 
driven type may be used. 

3. Street System Carrying any Pressure: "WTiere street steam 
service is maintained, the modulation system is similar in most respects 
to either Case 1 or 2 described above, except that no provision is made for 
returning the condensation to the boiler by a modulation vent trap, as in the 
case of a low-pressure heating boiler, or by some form of return pump where 

164 



higher pressures are carried on the boiler. The water of condensation is 
usually discharged to the sewer through a meter in the return line, except 
where a flat rate per square foot of radiation is charged in which case no 
meters are used. 

Where exhaust steam at 1 or 2-lb. pressure is supplied by the street 
service, a connection is made directly from the main to the supply 
piping in the building. If steam at higher pressures is furnished, a pressure- 
reducing valve is placed between the service connections and the main 
heating pipe, to regulate the steam to any desired initial pressure on the 
system. By this means the pressure may be controlled to best suit outside 
temperature and weather conditions. 

Webster Vacuum Systems 

Webster Vacuum Systems may be sub-divided into four classes, accord- 
ing to the source of steam supply: 

1. High-pressure or power boilers, with exhaust steam available from 
engines and auxiliaries. 

2. Medium-pressure boilers, 15 to 50-lb. pressure. 

3. Low-pressure boilers up to 15 -lb. pressure. 

4. Street systems. 

1. Webster Vacuum System with Power Boilers: With this 
type of vacuum system the source of steam supply may be 

(A) Exhaust steam from the engine; or 

(B) Exhaust steam from engines or auxiliaries, supplemented by 
live steam at reduced pressure. 

In the Case A when the power load exceeds the heating load, the supply 
of exhaust steam will be ample for the requirements of the heating system 
and in addition may also be used in a Webster Feed-water Heater to preheat 
the water supplied to the boilers. Under such conditions the heating plant 
is exceedingly economical since it utilizes a by-product, exhaust steam, 
which otherwise might be wasted. 

It is under such conditions that the Webster Vacuum System is most 
advantageous since it ensures a rapid circulation of steam through the 
entire heating system with a minimum back pressure on the engine. The 
reduction in back pressure saves in the steam consumption of the engines. 

In the Case B where the quantity of available exhaust steam is not suffi- 
cient, live steam at reduced pressure is automatically admitted into the 
heating main to make up the deficiency. In this design of heating plant, 
care should be exercised to see that all of the exhaust steam is utilized, 
including that from the various pumps and auxiliaries. 

Fig. 15-2 illustrates a conventional layout in elevation, of a Webster 
Vacuum System, using both exhaust and live steam in combination with 
a Webster Feed-water Heater. 

Referring to the illustration, the exhaust steam is made suitable for 
efficient heating and for subsequent use, when condensed, by passing 
through a Webster Oil Separator, which must be properly dripped. 

It is very important that the oil separator shall be properly dripped. 

165 



^UEj 36EJ01S 




166 



For ordinary cases, where the pressure in the exhaust main is maintained 
above that of the atmosphere, the Webster Grease Trap, also shown in the 
iUustration, is highly efficient. A daily inspection of the grease trap 
should be made while the plant is in use, to be sure that it is operating 
properly. In systems which lie idle for a portion of the year, a careful 
examination should be naade on starting up, to see that the grease trap and 
the pipe connections thereto have not become clogged on account of the 
solidification of the grease during the period of such idleness. Failure 
of the trap to function properly will cause the separated oil to be carried 
over into the heating system and eventually to reach the boilers, where it is 
very likely to produce bagging or blistering of the shell plates and tubes. 

If the partial vacuum created by the vacuum pump extends into the 
heating mains, at times when the supply of exhaust steam is insufficient, 
and it is not supplemented by live steam, it will be necessary to drain the 
oil separator in a special manner. Figs. 24-27 and 24-28 in Chapter 24 
show both methods of draining the oil separator. 

The necessary live steam is admitted through a pressure-reducing 
valve of a suitable size and type. A Webster Water Accumulator is used, 
as shown in the illustration, lo ensure proper functioning of the valve.. 
The addition of a pop safety valve in the low-pressure main, set to blow 
at a few pounds above the normal working pressure, will give warning of 
any tendency of the reducing valve to build up pressure during periods 
when the demand for steam is very light. 

Dripping Supply Mains and Risers: Supply and return mains and 
risers should be sized and run as recommended for vacuum system practice 
in Chapter 11. The method of dripping mains and risers into the vacuum 
return line varies with the local conditions of each building. In the typical 
illustration the base or "heel" of the main supply riser is shown dripped 
through a Webster Heavy-duty Trap, protected from scale and sediment 
by a Webster Dirt Strainer. 

A few general suggestions regarding the dripping of supply mains and 
risers will be helpful and will assist in determining which of the several 
methods of application will be followed. 

As stated in the description of modulation systems, the overhead or 
down-feed system of supply piping is employed in tall buildings and in 
buildings of certain types where it is desirable to avoid the running of large 
supply mains in the basement. Steam is conveyed through a main up-feed 
riser to a distributing main located either on the ceiling of the top story or 
in the attic space above. The space should have sufficient head room to 
give easy access to the valves which are generally placed in the run-outs 
from the main to the riser, and also to permit future repairs. It is needless to 
say that either the attic floor should be made strong enough to carry the 
weight of a man or a narrow platform should be provided. Either can be 
made of two 2-in. thick, hard pine planks of 24-in. total width and sus- 
pended by iron hangers fastened to the roof framing and spaced at regular 
intervals. The platform should run parallel to pipe lines and close enough 
to allow a man suitable space for working. 

The main riser is dripped through a Webster Heavy-duty Trap and 

167 



Webster Dirt Strainer, as shown in Figure 22-2. The drop risers are in- 
dividually dripped through Webster Return Traps, with proper provision 
for cooling surface between the point of drainage and the trap, the sur- 
face being arranged either horizontally or vertically, as space conditions 
may determine. As dirt and scale are more apt to accumulate at such drip 
points than elsewhere in the piping system, it is essential also that the traps 
be protected by means of dirt pockets made up of pipe and fittings, as 
shown in Figs. 22-7 and 22-8, or by means of W^ebster Dirt Strainers, 
shown in Fig. 22-10. The latter are simple, self-contained fittings, easy to 
install, and convenient and readily accessible. The cleaning of these points 
where dirt accumulates is essential to the success of the heating system. 

Another method of dripping the drop risers of down-feed systems, 
which is very satisfactory where building conditions permit its use, is to 
connect all of these risers into a wet-return or gravity drip line. This 
necessitates the running of a separate wet-return line in the basement 
along the floor. In such case, return traps are not needed for dripping the 
risers, but each riser must connect to the gravity drip line through a hori- 
zontal line in which an efficient check valve is placed. Various methods of 
•accomplishing this are shown in Figs. 22-28, 22-29 and 22-30 in Chapter 22. 

Where building conditions justify the running of a basement supply 
main, with a series of up-feed risers, each riser is dripped through a Webster 
Return Trap, protected by a dirt pocket or Webster Dirt Strainer, into 
the vacuum return line. The main itself is dripped at various points 
where it rises or where its size is reduced, so as to relieve the condensation 
and air which would otherwise accumulate and interfere with the proper 
circulation of steam. These points are also dripped through Webster 
Return Traps, properly protected from dirt and sediment. Provision for 
cooling surfaces in the pipe connection to the return trap is of prime impor- 
tance with this method of dripping. (See Figs. 22-31, 22-32 and 22-33.) 

Very tall buildings sometimes require a combination of the up-feed 
and down-feed system of supply, with a combination of the various methods 
of dripping. 

The drip at the base of a main up-feed riser is commonly referred to 
as a "main riser drip" or "drip at heel of main riser." Drips at the bottom 
of up-feed or down-feed risers where traps are used are called "supply riser 
drips." Drips at various points on the basement main are called "main 
drips." Wet -return lines are called "gravity drips." 

Supply lines to fan heater coils, hot-water generators, etc., usually 
require separate drips, using either Webster Heavy-duty Traps or Webster 
Return Traps, depending upon the volume of condensation to be handled. 
Where such drips are to be taken into the vacuum return line comparatively 
close to the vacuum pump, special provision must be made on account of 
the relatively high temperature of the condensation. 

Supply lines to apparatus requiring steam at pressure above 15-lb., 
known as medium or high-pressure lines according to the pressure carried, 
should not be dripped directly into the vacuum return line. Special methods 
of taking care of such drip points must be followed. Figure 20-2, Page 203 
shows one method. 



168 



Radiator Connections: Regardless of the arrangement of the supply 
mains and risers, and the methods of dripping them, the supply connections 
to the individual radiators will be similar, as shown in Figures 22-14, 22-15 
and 22-19. 

Horizontal connections, known as "laterals," are taken from the 
supply riser to the radiator. In the case of radiators with top-feed connection, 
a vertical supply line will be taken from the lateral to the radiator supply 
valve. This applies particularly to radiators of the hot-water type, in which 
the radiator sections are connected together at the top by means of close 
nipples. Sometimes steam radiators may be similarly fed, using the first 
section to convey the steam in a downward direction, particularly where a 
fractional-control or modulation valve is used with this type of radiator. 

In Chapter 12 special attention is called to the necessity for proper 
sizing and grading of these laterals. 

In Figure 15-2 the cast-iron column radiation is shown supplied 
through a Webster Modulation Valve, while the heating coil is supplied 
through an ordinary gate valve. 

The advantage of the Webster Modulation Valve is that it provides a 
convenient, positive means of throttling the steam supply to each radiator 
so that the occupant of each compartment may maintain the temperature 
which he desires, without regard for the temperature in any other compart- 
ment. This results not only in increased comfort to the occupant, but in 
decrease of the amount of steam used, as the room temperature is varied 
by manipulation of a single valve on each radiator, and not by opening and 
closing windows. This latter method is the customary and inefficient way 
of varying room temperature where ordinary supply valves are used, owing 
to the inconvenience and uncertainty of such valves in throttling the sup- 
ply of steam. 

The Webster Modulation Valve, described and illustrated in detail 
in another chapter, is especially designed to give perfect modulation of 
room temperature with less than a full turn of the indicator, the position of 
the indicator on the dial showing the degree of opening. Further, during 
the period of initial warming-up of a cold room, it acts as a quick-opening 
valve and where the proper sizes are selected for the operating conditions, 
the radiator ivill be heated all over in 20 minutes, after which, if the weather 
conditions are such that a smaller volume of steam is required to viaintain 
the room temperature, the indicator is turned back, and steam is conserved. 

Radiators may be placed in exposed locations beneath windows or 
between columns, as shown in Figure 15-2, or may be wholly or partially 
concealed under window seats or behind grilles (Figs. 6-14 and 6-15) ; or may 
be located overhead as with skylight coils (Fig. 5-2). 

Each of these conditions requires special arrangement of supply con- 
nections and fixtures. Some helpful suggestions to meet particular connec- 
tions may be found by studying Webster Service Details in Chapter 22. 

Whether to employ Webster Modulation Valves or ordinary radiator 
supply valves is optional with the architect or designing engineer who 
selects the equipment. The modulation type is recommended wherever 
efficiency and economy of operation are desired, as the additional first 
cost of installation is very little, and repairs and upkeep are negligible. 

169 



They are especially to be recommended in hotels, apartment houses 
and other buildings with transient occupants who have no incentive to 
economize in the use of steam where ordinary valves are used. Also greater 
economy may thus be secured in dormitories, schools, institutions, etc., 
where the manipulation of the radiator valves is under control of a regular 
attendant rather than the occupant of the room. For such cases, a lock- 
shield type of Webster Modulation Valve with key is frequently used. 

The Webster Vacuum System is admirably adapted for use where 
special systems of automatic temperature control are used, as in large office 
buildings, hotels, etc., to control individual room temperatures. 

Disposal of the Products of Condensation: The air, gases and water 
comprising the products of condensation of steam within the radiators, 
are drained from each radiator by a Webster Return Trap connected at 
the return end. Lateral "run-outs" conduct this condensation to a series 
of return risers which convey it to a system of basement return mains, 
in which a partial degree of vacuum is maintained by a steam or electrically 
driven vacuum pump, according to conditions. 

The Webster Return Trap serves the triple function of relieving the 
air and gases as well as the water of condensation and also preventing the 
escape or loss of steam into the return line. 

Air valves are unnecessary. Their annoyances and discomforts are 
entirely eliminated. 

The several types of Webster Return Traps and the various methods 
of application for different conditions are explained in other chapters. 

As with laterals from supply risers, return run-outs to risers must be 
properly sized and graded. This is a detail which often requires personal 
inspection during the progress of the installation, particularly where the 
laterals and run-outs are run in pipe or sheet-metal sleeves which in turn are 
embedded in concrete or other solid floors. 

The Vacuum Pump: The vacuum pump and its auxiliary equipment 
may be referred to as the heart and lungs of a vacuum system. It is all- 
important that they be properly selected and sized, and that the function 
of all parts of this equipment be thoroughly understood so that the piping 
connections will be properly made. (See Chapter 13.) 

Various types and arrangements of equipment are necessary to meet 
different conditions. 

In the type of vacuum system which is now being described, the vacuum 
pump will usually be of the steam-driven reciprocating type, steam being 
furnished directly from boilers at relatively high pressure. 

The supply of steam to the pump is automatically controlled by a 
Webster Vacuum-pump Governor actuated by the degree of vacuum 
existing in the vacuum return line and adjusted to stop or slow down the 
operation of the pump as the vacuum approaches the point for which the 
governor is set, and starting or speeding up the pump as the vacuum drops 
below this point. 

The pump, where of the reciprocating type, is lubricated by the admission 
of cylinder oil into the steam supply line through a sight -feed lubricator, 
or if preferred, through a mechanical force-feed oiler, the latter being attached 

170 



to the pump preferably before shipment and actuated by the operation 
of the pump itself. 

The suction valves of the pump are protected from dirt and foreign 
material by a Webster Suction Strainer. 

The products of condensation will be conveyed by gravity through the 
system of return risers and main vacuum-return line to a point either above 
or below the suction inlet of the pump, depending upon building conditions. 

If this point is below, the vacuum pump will raise the condensation 
with its entrained air. The arrangement of "lifts" depends upon the ver- 
tical distance and degree of vacuum created and maintained by the pump. 

Webster Lift Fittings used in pairs will materially assist the 
vacuum pump where lifts are necessary. 

Various methods of applying vacuum-governors, lubricators, suction 
strainers and lift fittings in connection with vacuum pumps are shown in 
the Webster Service Details in Chapter 13 in which the practical problems 
of installation are worked out. 

Final Disposal of the Condensation: The vacuum pump discharges 
the products of condensation to a point of disposal, where the entrained 
air is liberated and the condensation returned to the boiler as feedwater. 

In Figure 15-2 the pump discharges into a Webster Receiving Tank 
which is vented to the atmosphere. The condensation flows by gravity 
from the tank to the Webster Feed-water Heater against the working 
pressure carried. 

In the typical case, the receiving and air-separating tank is of the 
water-control type, and the Webster Feed-water Heater also has an auto- 
matically controlled valve in its water-supply line. 

As the water level in the Feed-water Heater lowers, the automatic 
valve opens, and the condensation flows from the tank to the heater through 
the sealed connection. This arrangement of tank and heater may be used 
only where the tank can be located at sufficient height above the heater 
so that the static head will overcome the working pressure within the heater. 

Additional fresh water required to make up any losses that occur is 
admitted automatically into the tank by the lowering of the water level, 
which in turn actuates the automatic water-regulating valve. 

Surplus condensation overfiows from the tank to the sewer or drain. 
The waste of condensation at higher temperature from the overflow of the 
feed-water heater is thus eliminated. 

An alternate arrangement which is often desirable is the use of a 
Webster Receiving Tank of the plain type with a Webster Feed-water 
Heater of the Steam-control Type, as is shown in Fig. 27-7, Page 304. 

In this case the condensation flows continuously from the tank to the 
heater. As the water level in the heater rises, the automatic valve, placed 
in the steam line to the boiler-feed pump and actuated by the water level in 
the heater, causes the pump to withdraw the water from the heater. 

Another arrangement is the use of a Webster Tank of the plain type dis- 
charging into a special return inlet on the heater, fresh water as needed 
being automatically admitted into the heater. (See Fig. 27-6, Page 303.) 

Still another arrangement which is necessary where the tank cannot be 

171 



located at sufficient height above the heater to overcome the pressure therein, 
is the use of a Webster Hydro-pneumatic Tank, described in Chapter 13. 

Where an open feed-water heater is not used, the tank discharges to the 
boiler-feed pump, either the water-control or steam-control type of pump 
being used, according to conditions. 

The specific functions of each of these types of Webster Receiving 
Tanks are more particularly described in Chapter 24. 

Ventilation Problems: In Figure 15-2 a typical installation of a motor- 
driven ventilating fan, with its re-heater and tempering coils, is also shown. 

The fan heater supply line is dripped through a Webster Return Trap 
and Dirt Strainer, and the individual heater sections through Webster 
Return Traps. 

The method of dripping fan heater sections will vary with the size, 
arrangement and number of sections. Special study should be made of the 
various Webster Service Details shown in Chapter 22. 

It is exceedingly important not only to choose the right type of trap 
for use with indirect radiators but also to have the pipe connections properly 
made. The trap must be of the highest efficiency, with sufficient capacity 
to pass rapidly the maximum quantities of water and air which are present 
when first warming up, and afterwards open for the condensate and entrained 
air but absolutely prevent the escape of steam. This must be done even 
where core sand and greases are present and settle in the valve bodies. Where 
groups of radiators are made up of large numbers of sections nippled to- 
gether, there is a likelihood of air-binding sometimes extending over con- 
siderable areas. This trouble can be avoided if the traps and piping 
are right. Webster Return Traps and Webster Heavy-duty Traps meet 
every condition if installed in accordance with proper Service Details. 

Further reference should also be made to other chapters for description 
and method of application of various types of Webster Feed-water Heaters 
where power boilers are used for generating steam for prime movers ; Webster 
Steam Separators placed in the high-pressure steam lines to provide dry 
steam for engines; and Webster Expansion Joints, of both the single and 
double-slip pattern, for low and high-pressure steam lines, to take care of 
the expansion and contraction which occur in such lines. 

2. Webster Vacuum System With Medium-Pressure Boilers, 
15 TO 50-LB.: The foregoing description will serve as a general description 
of this type of vacuum system, except that the feed-water heater will not 
be used, the exhaust steam will be limited to that from pumps and auxiliaries, 
if steam-driven, and the vacuum pump will be either of the low-pressure 
steam-driven type or electrically driven. 

Under some conditions, particularly for pressures up to 20-lb., 
electrically driven pumps may be more suitable, and in these cases the 
lubricator and vacuum-pump governor will not be used. 

For boiler pressures up to 15-lb., either electrically operated re- 
ciprocating vacuum pumps or steam-driven pumps can often be used in 
conjunction with Webster Hydro-pneumatic Tanks to return the water to 
the boiler without the use of a separate boiler-feed pump. Webster Service 
Details in Chapter 13 show the proper arrangement for such cases. 

172 



3. Webster Vacuum System With Low-Pressure Boilers, up to 
15-LB.: The description of this type of vacuum system is the same as that 
immediately preceding, except that the rotary type of electrically driven 
vacuum pump, handling air and water separately, is particularly suitable. 
These pumps also act as boiler-feed pumps if the conditions of the plant 
are within the range of the discharge head or pressure at which the manu- 
facturers guarantee these pumps to operate. 

4. Webster Vacuum System. Steam Furnished from Street 
System: As steam at a pressure suitable for operating a steam-driven 
vacuum pump is usually not available, this type of vacuum system will 
require either rotary or reciprocating electrically driven vacuum pump. 

The condensation in such cases is discharged to the sewer or point 
of disposal through a condensation meter of a type for vacuum service. 

Webster Vacuum Systems, Special Modifications: There are 
two special types of modifications of Webster Vacuum Systems which will 
require special description: The Webster Conserving System and the 
Webster Hylo Vacuum System. 

Webster Conserving System: This is a special modification of the 
Webster Vacuum System which meets two general conditions: 

1. Where necessary to operate steam-driven pumps from low-pressure 
boilers at very low pressure — from 5 to 20-lb. 

2. Where necessary to provide steam for some special service con- 
tinuously at a pressure higher than that needed for heating. 

Referring to Figure 15-3, this system is in general respects similar to 



WEBSTER 
CONSERVING VALVE 



This Connection to be made 15'-0'' 
from Pressure Reducing Valve 
WEBSTER 1 

WATER ACCUMUUTOR , 



Gale Valve 



WEBSTER HORIZONTAL 
OIL SEPARATOR 




/This Valve to be open when 
Pump is started and closed 
when Pump is in operation 



.Globe Valve 

Checit Valve 



Bypass to Sewer^ I 'WEBSTER SUCTION STRAINER 

WEBSTER LIFT FITTINGS 

Fig. 15-3. Typical layout of a Webster Conserving System 

173 



^WEBSTER GREASE 
AND OIL TRAP 



the vacuum system described for working pressures from 15 to 50-lb. pressure. 

A low-pressure steam-driven vacuum pump is used, discharging to a 
Webster Hydro-pneumatic Tank, and thence to the boiler against pressure. 

The distinguishing feature of this special system is the Webster Con- 




Fig. 15-4. Typical installation and close-up of the Webster Conserving Valve 

174 



serving Valve, which is placed in the supply main near the boiler, and 
conserves or retains the steam on the inlet side of the valve until sufficient 
pressure has been built up to (1) operate the pump, or (2) meet the pressure 
requirements of the special service. 

Connections to the vacuum pump or for the special service are taken 
from the high-pressure side of the conserving valve. When the predeter- 
mined pressure has been built up, the excess pressure is released into the 
heating main by means of the conserving valve. 

In consequence, the vacuum pump begins to function before the steam 
enters the heating main and continues to operate even when the pressure 
drops on the high-pressure side to such point that the conserving valve closes 
against further admission of steam into the heating main. The heating 
system is therefore kept continuously drained of water at all times, insuring 
return of condensation to the boiler and preventing accidents or damage 
which would occur from lowering the boiler water level to a dangerous point. 

One other special feature of this system is the use of a Webster Damper 
Regulator to control the boiler pressure, operating from the low-pressure 
side of the conserving valve. The damper regulator must be connected 
in the special manner recommended. 

In a similar manner to the above, any special apparatus like kitchen 
equipment requiring steam continuously at higher pressure is always 
assured of constant supply regardless of operation of the heating system. 

Another adaptation of the Webster Conserving System is in large 
plants in which the engines are run condensing. 

A study of steam engine performance, where the engine exhausts into 
the atmosphere or into the heating system aga nst a back pressure slightly 
above that of the atmosphere, shows that engines working under such 
conditions actually convert only 5 to 10 per cent of the heat supplied to 
them into mechanical energy. The remaining 90 per cent of the heat origi- 
nally supplied to the steam entering the engine is retained in the exhaust. 

In some plants, power and heating loads are nicely ba anced so that all 
the exhaust steam available from power units can be utilized for process work 
or heating purposes, in which event the 90 per cent of heat energy remaining 
in the exhaust steam is put to useful work. In such cases the engine may be 
considered as a pressure-reducing valve which reduces the pressure from 
that carried on the boilers to that required for heating and process purposes. 

There are numerous industrial plants where the power load is greatly 
in excess of the heating load, so that the quantity of exhaust steam available 
is greatly in excess of that actually required. The surplus exhaust steam 
with its heat units must then be wasted. 

Where these conditions exist, the engines are often operated condensing 
instead of non-condensing, so that exhaust steam from the auxiliary ma- 
chinery only is available. In most instances the quantity is not sufficient 
to supply the heating load, and the deficiency is made up by live steam 
supplied from the boiler through a pressure-reducing valve. 

The work done by the pressure-reducing valve in reducing the steam 
from boiler pressure to that required in the heating system is converted 
into superheat on the low-pressure side of the valve. This work represents 

175 



about 10 per cent of the total heat energy supplied to the steam. If this 10 
per cent of heat energj^ can be utilized by conversion into mechanical energy, 
nearly ideal conditions will be approached. 

Various attempts have been made in the past to improve the economy 
of power and heating plants by endeavoring to utilize the exhaust steam 
from the receivers of compound engines. This exhaust is bled into the heat- 
ing system and the deficiency made up by admitting live steam into the 
receiver through a pressure-reducing valve. In determining the advisability 
of this form of application, the effect of the relations between heating and 
power load and the relative proportion of the cylinders so vitally affects 
the economy that in each instance special consideration has to be given to 
all elements entering. 

The Webster Conserving System can be applied to this problem. In 
the same manner that the conserving valve is applied to conserve the 
pressure on the boiler by preventing the escape of its steam until a certain 
predetermined pressure is obtained, it can be applied to the receiver of a 
compound engine, opening and admitting steam at receiver pressure into 
the heating system, when the pressure on the receiver exceeds that which 
is necessary for the proper operation of the low-pressure cylinder, and 
closing when the receiver pressure drops below the point for which the con- 
serving valve is set. 

The quantity of steam taken from the receiver is made up by changing 
the cut-off on the high-pressure cylinder so that the high-pressure side 
acts as a pressure-reducing valve for the steam required for heating purposes. 
In expanding from boiler pressure to the receiver pressure, the heat energy 
given up in the expansion is converted into useful mechanical energy. 

By means of the Webster Conserving System many existing power and 
heating plants may be brought to efficiency where they are otherwise 
wasteful of steam. 

Webster Hylo Vacuum System: Where a number of buildings 
must be heated from a detached central plant, or where a building covers 
considerable ground, the source of steam supply and of vacuum cannot 
always be located to make a well-balanced system. 

The largest building in the group may, for various reasons, be farthest 
from the source of supply, and may also be the lowest point in the system 
of return piping, thus making it doubly difficult to secure perfect heating 
and easy return of condensation. Nearby points may be favored with 
unnecessary pressure difference. 

Attempts have been made to solve this problem by running the supply 
and return mains in reverse direction, so that the point of highest pressure 
is the point of lowest vacuum and inversely, thus maintaining, in some 
degree, the same differential between supply and return pressures. 

Where the largest building is at a low point away from the source of 
supply, it is obviously impracticable to solve the problem in this way. 
Furthermore, such a plan does not allow for extensions to or expansion of 
the plant, unless the new buildings can be located to suit the piping 
scheme, irrespective of the manufacturing need. 

This problem has been solved with unquahfied success by Webster 




Gate Valve 



Floor Line--- 



Fig. 15-5. Connections around 
Webster Hylo System equip- 
ment where the low-vacuum 
return main drops from over- 
head and discharges through 
a Webster Hylo Trap to the 
high-vacuum return main 



Fig. 15-6. Typical installation 
of Webster Hylo Trap, Con- 
troller and Gauges where high 
and low-vacuum returns are 
on the same level 



Gauge Cock 



iauge Cock 




-Gale Valve 



Line- 



Gauge Cock 



Connect to High 
Vacuum Returns 

/ J^ WEBSTER 



ushing Gate Valve -^ Bushing^^^^Gaugg Cock 




V^EBSTER 
HYLO VACUUM CONTROLLER 

Union 




By-Pass on Side' 



Fig. 15-7. Arrangement 
of the Webster Hylo 
Controller, Trap and 
Gauges where the low- 
vacuum return is lifted 
to the high-vacuum 
return 



177 



Hylo Vacuum Controlling Sets, which are installed at certain points in the 
return line to restrict the vacuum to just the amount necessary for proper 
circulation and drainage at nearby points where high vacuum is not needed. 
The high vacuum is carried to extreme or low points where high vacuum 
is required. The result is a well-balanced system with perfect circulation 
in all parts. 

The operation of the vacuum pump is also improved to a marked extent 
as the degree of initial vacuum is reduced, making it unnecessary to use or 
waste cold water to condense the vapors arising from the hot water returned 
under high vacuum. Sometimes smaller pumps may be used, or the pumps 
may be operated at slower speed with less wear and tear. 

The Webster Hylo Sets consist of a Webster Hylo Trap, a Webster 
Hylo Vacuvuii Controller, Webster Hylo Vacuum Gauges, and when needed, 
Webster Lift Fittings. 

Figures 15-5, 15-6 and 15-7 show various methods of connecting Webster 
Hylo Sets to meet different building conditions. 



178 



CHAPTER XVI 

Application of the Webster System to Lumber and 
Other Kiln Drying Problems 

PROPER seasoning and drying of raw lumber is a first essential to well- 
finished products in any wood-working industry. 
This basic condition makes the dry kiln or room a most important 
feature, for as proved by experience in many instances, lumber that was found 
defective when worked would have been satisfactory if proper methods had 
been applied for drying. Very careful attention should therefore be given 
to the design of the drying room, the character of apparatus used and the 
heating medium employed. 

The method to be employed in drying will depend entirely upon the 
condition of the product when put in the kiln. Green lumber, or lumber 
having a high percentage of moistxire, will require a different method of 
procedure, and a longer time to dry than lumber which has been air dried. 
Hard woods such as oak or hard maple usually require a longer time than 
soft woods. 

Saw mills should determine the percentage of free moisture by test and 
so mark each pile of lumber when first piled in the yard. Later, when it is 
sold, the lumber should be tested again and the two records given to the 
factory or other purchaser. 

Factories should test and mark the lumber when first received, and if 
it is piled in the yard to be kiln dried later, it should be tested before going 
to the kiln and again before removal, these records being placed on file. 

The process required for the drying of lumber in kilns is properly 
divided into four parts, as follows: 

First: The primary treatment, during which all dampers are closed, 
100 per cent humidity is maintained and the stock is warmed through 
without drying. 

Second : The initial drying period, during which the conditions of tem- 
perature and humidity within the kiln are advanced sufficiently to reduce 
the moisture content to 25 per cent. 

Third: The intermediate drying period, during which drying condi- 
tions are still more advanced to reduce the moisture content to 10 per cent. 

Fourth: A final drying period, during which extreme conditions are 
used to further reduce the moisture content to the percentage desired. 

Improper drying methods will usually result in one or more of the fol- 
lowing conditions: 

(1) Percentage of moisture not correct for working, (2) case hardening, 
(3) hollow-horning or honey-combing, (4) molding. 

The operator should make careful test readings to determine the mois- 
ture content both before and during the drying of the lumber. 

Records from such tests will give data on which to base his treatment 
of the stock. Tests should be made at stated intervals of 48 to 72 hours 

179 



during the drying period. For this purpose test boards from which samples 
may be taken should be inserted in the kiln. A good solid heavy piece as a 
sample, or better still, two or more sections out of as many different boards 
taken out of the pile one-third the distance from the bottom, will yield an 
average or representative test for moisture content. With two or more 
tests for moisture showing varying results, it is safer to use readings showing 
the highest moisture content rather than the average of the pieces. 

At the same time, tests should be made for case hardening. If the 
lumber becomes case hardened, it practically stops the drying process, or 
at least slows it to a great extent. Frequently this results in hollow-horning, 
cupping, internal strains and many other evils which affect the stock through- 
out the manufacturing process. 

Almost all '"working" which occurs in furniture, or other wood articles, 
is due to stresses which developed in the wood during the seasoning period. 
These stresses may be determined by two simple tests and eliminated before 
the stock leaves the kiln. 

The manufacturers of the different makes of dry kilns furnish detailed 
instructions for the various tests on which the successful operation of their 
kilns depend. 

The final condition of the lumber required in different factories varies 
with the purpose for which the lumber is used. For instance, in wagon 
work, many manufacturers do not use lumber containing less than 10 to 
12 per cent of moisture; in auto body work, for open bodies, 6 to 8 per cent 
is considered proper; for closed bodies, 5 to 6 per cent. Furniture manufac- 
turers generally dry down to 4 to 6 per cent, while wheel manufacturers 
dry the spokes as nearly bone dry as possible, but do not dry the felloes 
below 8 per cent, the theory being that when the wheel is made the spokes 
may absorb moisture and make a snug fit. 

A modern kiln is usually constructed with brick side walls and a roof 
of tile or cement covered with roofing felt, tar and gravel. The doors are 
of special design to allow for easy loading and unloading, and to prevent, as 
much as possible, air leakage and loss of heat. Ventilating flues are provided 
in the side walls for supplying air and removing same as desired. 

The heating medium usually employed is steam at varying pressures, 
depending upon the kiln temperature desired. The temperature within 
the kiln is controlled by means of a thermostat operating a valve in the pipe 
supplying steam to the coils. 

A system of steam spray pipes is provided under the material to be dried 
for increasing the humidity as desired and to assist in warming the stock. 
The percentage of humidity in the kiln may be automatically controlled by 
means of a humidistat operating a valve controlling the supply of steam to 
the spray pipes. 

Where steam, whether exhaust from engines and auxiliaries, or taken 
direct from the boilers, is used as a heating medium, the success of the 
drying equipment depends upon the manner of carrying this steam to the 
heating units, the proper drainage of the supply mains, the circulation of 
the steam through the heating units and the removal of air and water of 
condensation. 



180 



All manufacturers of drying equipment utilizing steam as a heating 
medium recognize the importance of these features. One of the largest 
manufacturers of drying equipment in the United States says in its book of 
instructions : 

'"Where troubles have been experienced, investigations have shown that 
they are generally due to one or more of the following conditions : 

"Poor steam service. 

"Pressure not constant. 

"Wet steam due to improper condensation drainage. 

" Insufficient steam pressure. 

"Poor drainage from traps. 

"Improper design of supply and drainage piping. 

"Traps allowing steam to blow through into the main drainage line, 
holding back kiln drainage. 

"Traps on heating units not functioning properly. 

"Traps stopped with scale or dirt. 

"Trouble is often caused by faulty design in making steam connections 
to kilns. 

"All steam lines must pitch in the direction of steam flow. Automatic 
drain traps must be provided at all low points on these lines in order that 
there may be absolutely no condensation lying in the lines at these places, 
and that steam may enter the kiln dry and at a high temperature. Failure 
to provide proper methods of drainage will result in reduced volume and 
temperature of steam and correspondingly low temperatures and poor serv- 
ice in dry kilns." 

The important features in connection with the steam supply and drain- 
age system can be enumerated as follows. 

(1) Adequate and continuous supply of steam. Pressure of steam con- 
stant and sufficient to produce the required temperature within the kilns. 

(2) Manner of conveying steam to coils. 

(3) Method of draining main steam supply. 

(4) Character of design of heating vmits. 

(5) Method of complete and rapid air removal from heating units and 
from entire return system. 

(6) Method of removal of condensation from heating units. 

(7) System of drainage piping. 

(8) Ultimate disposal of water of condensation and of air. 

(9) Adequate and continuous pitch of pipes throughout the entire 
length of the coil. 

Items one, seven and eight will be governed materially by the condi- 
tions existing at the plant where kilns aie to be used, and as these conditions 
vary with the character of the plant, this discussion will be limited to the 
requirements of the kiln only. 

The pressure of steam supply, so far as the operation of the kiln is con- 
cerned, will depend upon the temperature required within the kiln. If a 
maximum kiln temperature of not more than 150 deg. fahr. is required, satis- 
factory results can be obtained by the use of exhaust steam from engines 
and auxiliaries at a pressure not to exceed 1 J^-lb. gauge. The same results 

181 




Vacuum Return 



A Typical Elevation 




A Typical Plan 

Fig. 16-1. Sections through a typical dry kiln with coils of the continuous-header type using Webster 
Heavy-duty Traps for drainage and Webster Return Traps for removal of air from return headers 

182 



will be obtained, of course, by using steam direct from the boiler, reduced 
to a corresponding pressure by means of reducing valves. It is very impor- 
tant to place a relief valve on the low pressure side of the reducing valve to 
prevent rise of steam pressure to a point where there is a liability of injur- 
ing the thermostatic return traps. The details are shown in Fig. 22-3, 
Page 216. 

Where temperatures greater than 160 deg. fahr. eu"e required it will be 
necessary to increase the pressure of the steam accordingly. In good 
practice the temperature of the steam must not be less than 60 degrees 
higher than the temperatiu-e desired in the kiln. 

The size of the steema supply mains will depend upon the volume of 
steam to be delivered, and the drop in pressure allowable. This may be 
determined with the help of the tables in Chapter 11 in this book after a 
decision has been reached as to the total heat requirements of the kiln and 
the distance of the kiln from the soxirce of steam supply. The same prin- 
ciples apply for the installation of steam mains to the kilns as would apply 
for the installation of steam mains for any other purpose. 

Extreme care should be given to the drainage of the steam main at the 
point of entrance to the kiln. It is advisable that water of condensation 
from the main shall be relieved from the bottom into the return and that 
steam for kilns shall be taken from the top of the main rather than to allow 
the condensation to drain through the coils. The supply main may enter 
the kiln from a point above the coils used for heating, or from below them. 

Manufacturers of drying equipment have devised numerous types of 
heating units but practically all have standardized on those constructed of 
pipe. The coils are placed either vertically along the side walls of kiln, or 
horizontally in a space provided underneath the material to be dried. In 
the latter instance they are usually installed in a horizontal position, although 
some manufacturers prefer coils placed vertically. The advantage of more 
equal heat distribution is claimed for the large unit laid horizontally, but this 
is not fully realized unless the removal of air and condensation is complete. 

With coils having short vertical headers, say 10 pipes high, it is very 
important to secure an equal distribution of steam to all of the pipes. The 
internal diameter of the supply header should be ample; 23^-in. is none 
too great. It is very important not to locate the inlet in such a position 
that steam will enter those pipes directly in front of it and passing tlxrough 
to the return header, tend to pocket the air in the other pipes. The re- 
moval of air will be very sluggish and meanwhile the efficiency of the whole 
coil will be low. A deflector placed within the header in front of the inlet 
wiU improve the steam distribution. A much better method is to have 
more than one inlet. These additional supply connections will also reduce 
materially the velocity of the entering steam. 

Figs. 22-21 and 22-22, on Page 220, show methods of splitting up the 
return header into two parts, for coils of more than 10 pipes, when there is 
a liabihty of air binding. 

With horizontal headers, particularly where of some length, the in- 
ternal diameter should be large and the niunber and location not only of 
supply openings but also of return and air vent outlets should be selected 

183 



with great care, so as to ensure uniform distribution of steam and complete 
removal of air and water. 

Practical experience has demonstrated that incomplete removal of air 
and condensation has caused unequal heat distribution throughout the 
kiln as well as a drop in temperature of from 20 to 50 per cent. The air 
must not only be removed from the coils but also must be rapidly and 
completely eliminated from the return system and discharged outboard. 

The selection of the proper type of trap to be used in any given case 
depends upon the steam pressure which it is necessary to carry on the coils 
to secure the requisite heating effect, the quantity of water which the trap 
must handle, the temperature of the room in which the trap is installed, 
the pressure in the discharge hne and the disposition to be made of the 
products of condensation. 

A continuous and uniform steam pressure of not over 3 to 5 lb., a 
moderate and uniform quantity of condensation to be handled, and a tem- 
perature of not over 80 deg. in the space where the traps are located, are 
the most favorable conditions for the successful operation of low pressure 
thermostatic traps. They should not he employed where the temperature 
requirements of the kiln necessitate carrying a continuous steam pressure which 
approaches closely the allowable maximum pressure of the trap. Traps on high 




Plan 
Fig. 16-2. Typical section through a dry kiln using coils of the sectional-header type 

184 



Dampers 



1 i 



■.'-:',,'..;; ~? ^''^/''yyy^'/^/ 






Vacuum Return Line from Colls' 



Supply to Coils 

^, Drip from Spray 
\ \ Pipe Supply 
^ Supply to 
Spray Pipe 



^r 



;;*■ 



Pipe Tunnel , 



Elevation 




Fig. 16-3. Sectional drawings of a typical small dry kiln using individual return traps for drainage of coils 



185 



pressure steam drips must never be permitted to discharge directly into the 
return pipe near the thermostatic traps on account of the liability of back 
pressure or water hanwier. The connection should be made at a point be- 
yond the traps, placing a check valve in the thermostatic trap return to 
prevent back pressure therein and in addition means should be employed 
for disposing of the high temperature vapor as shown in Fig. 20-2, Page 203. 

The types of heating units which are universally used and the manner 
of applying the Webster specialties for proper air removal and drainage of 
condensation are shown in Figs. 16-1 to 16-4 inclusive. Attention is called 
to the importance of providing a dirt strainer for the drain connection to 
each trap. Both the traps and strainers should be readily accessible. 
Where thermostatic traps are used they should be located where they will not 
be affected by the high temperatures of the kiln. This is usually accomplished 
by extending drain connections to the extreme front or rear of the kiln and 
placing the traps near the floor. 

On small units as shown in Figure 16-3, where thermostatic traps are 
used, additional provision for the removal of air is unnecessary, but where 
a large volume of condensation accumulates, additional provision for air 
removal is essential and heavy-duty traps should be used. Where the heating 
unit is of the continuous header type as shown in Figure 16-1 the air removal 
can be accomplished by the use of heavy-duty traps equipped with a ther- 
mostatically actuated air bypass within the trap and by means of additional 
thermostatically actuated air traps connected into the top of the main 
return header, as shown in Figures 16-1, 16-2 and 16-4. The number and 
location of these air traps is governed by the length and design of the main 
return header. The outlets of these air return traps should be connected 
into the main vacuum return line beyond the discharge connection of the 
heavy-duty trap. 

Where heavy-duty traps are used there should be a drop leg of from 
8 to 10 inches between the outlet on the return header and the trap inlet. 

Where it is desired to drain the condensation from two or more coils 
to one heavy-duty trap, or where the return header of the coils is of special 
construction divided into two or more sections and the condensation from 
all sections is drained by one trap, it is essential for the proper removal of air to 
equip each return header, or each section of the return header, with a ther- 
mostatically actuated return trap. The outlets of these traps should be 
connected into the main vacuum return line in the same manner as de- 
scribed above. 

Pipe coils and return pipe connections to traps must have a sharp 
downward pitch their entire length in the direction of the flow of conden- 
sation. The coil supports must be of a permanent character and so arranged 
that any subsequent settlement of the kiln structure will not affect the 
pitch of the pipes. 

The dischEQ-ge from all heavy-duty traps and thermostatically actuated 
return traps used in connection with kilns may be connected into a com- 
mon return line, but it is preferable that this return line from kilns shall 
be extended independently from the kilns to the vacuum pump, rather than 
to connect it into returns from the heating system of the manufacturing 

186 



plant or other equipment. The condensation rate 
from the kilns will fluctuate, depending upon the 
temperature within the kiln, the nature and con- 
dition of the product being dried and the outside 
temperature. Consequently, at times when the 
air removal and condensation rate from the kilns 
is high, trouble may be experienced with the 
operation of other equipment if connected to the 
same return line. Also, if the same efficient 
equipment is not used in connection with the 
heating system or other equipment, as is used in 
connection with the kilns, the poor operation of 
the heating system or other equipment will natur- 
ally reflect in unsatisfactory operation of the 
kilns. 

The amount and location of radiation in- 
stalled within the kiln will depend upon the loca- 
tion of the kiln, the temperature desired within 
the kiln, the steam pressure, and nature of pro- 
duct to be dried. This constitutes a special 
branch of engineering and engineers thoroughly 
familiar with this class of work should be con- 
sulted. 

The method for figuring the total radiation 
required by a given dry kiln Avill not vary from the 
descriptions given in detail in Chapter 5, except 
that during the warming-up period an additional 
heat factor is required to care for the moisture 
content of the lumber or other material being 
dried. 

Much of the general information on lumber drying was furnished for 
this Chapter by the National Dry Kiln Co., of Indianapolis, Ind. 




Fig. 16-4. Showing the connec- 
tions where two or more coils are 
drained through one Webster 
Heavy-duty Trap 



187 



CHAPTER XVII 

Application of the Webster System to Slashers 
and to Cloth and Paper- drying Apparatus 

SLASHERS are used in the textile industry for sizing and drying warps 
I or yarns before they are placed in looms to be woven into cloth. In 
these machines, steam is supplied usually to two cylinders, of 5 and 
7 ft. diameter, over which the yarn passes to be dried after sizing. 

Ordinarily the steam supply and the drainage connections are on op- 
posite heads of the cylinders, the connections passing through the cored 
shafts upon which the cylinders revolve. Steam is carried tlirough the 
mains to the slasher at about 80-lb. pressure and before it enters the 
cylinders is reduced to between 5 and 12-lb. per sq. in. by a pressure-reducing 
valve. The steam pressure in the cylinders of course always must be above 
that of the atmosphere as the rapid drying of the materials demands that the 
surface temperature of the cylinders shall be above the atmospheric boiling 
point. 

Owing to the light weight of the metal used in the construction of 
slashers, vacuum breakers, usually three in number, are provided in the 
head of the discharge side of each cylinder. These open when a partial 
vacuum occurs in the cylinder and prevent collapse of same. 

The condensation is raised to its point of removal from the slasher by 
means of troughs or buckets, usually three in number, attached to the in- 
side cylindrical surface. A pipe attached to each bucket carries the conden- 
sation to the hollow cylinder shaft and thence through the bearing to the 
outside. From there the condensation goes through the Webster Traps, 
etc., to the point of disposal. 

The Webster System for draining slashers provides the most efficient 
drying effect with least attention to the drainage equipment. It has suc- 
ceeded in overcoming entirely the frequent delays and slowing down of the 
manufacturing processes previously experienced with other devices. 

As will be seen in Figure 17-1, each cylinder is equipped with a Webster 
Return Trap, a Webster Dirt Strainer and a bull's-eye sight glass. 

The Webster Return Trap permits the free passage of air and water 
and closes against the discharge of steam. The Webster Dirt Strainer 
protects the trap from dirt and the sight glass enables the operator to see 
whether or not the drainage system is functioning. 

A bypass is provided around the drainage apparatus. When starting 
up, the bypass may be opened for a few minutes to permit the quick dis- 
charge of air. After starting, the slasher is drained automatically through 
the Webster equipment. 

A pressure sufficiently above that of the atmosphere must be carried 
in the cylinder to dry the goods and this is sufficient to discharge the con- 
densation and air through the Webster Trap, if free vent to atmosphere is 
maintained. There is no advantage in connecting the discharge of the traps 

188 



to a vacuum pump if sufficient vertical distance is available to allow a proper 
fall for the condensate to flow by gravity to an open receptacle. 

The condensation rate with this type of slasher will vary from 400 to 
600 lb. per hr. 

One of the best-known American manufacturers of slashers states in 
his catalog: 

"We strongly recommend the use of Warren Webster & Co.'s appara- 
tus for slasher drainage. 

"Steam traps can be furnished if desired but we recommend the use of 
the Webster System in preference, as higher economy will certainly maintain 





Long Sweep Tee !] 1 Gate Valve 

To Drain'' WEBSTER SIGHT GLASS 

Fig. 17-1. Typicail application of Webster Apparatus to a slasher 

189 



a higher rate of production and its simpUcity lessens the HabiUty of stoppage 
to which a system of steam traps is apt to be subject after a few years of use. 
" The Webster System as compared with a steam-trap system insures 
steady, instead of intermittent, drainage and practically an entire absence 
of condensation in the cylinder with all consequent advantages." 

Cloth and Warp Drying Machines: Except in details, the process 
of draining drying machines of both vertical and horizontal types is the 
same as for slashers. 

Each cylinder is provided with troughs or buckets which, as the cylinder 
revolves, empty tlirough a pipe to a hollow shaft and through the journal 
to the return duct. 



Air Vent open to Atmosphere 




^ Conned to Hot Well, or Drain independently 



Fig. 17-2. Application of the Webster Apparatus to a vertical drying machine 

A. Solid copper gasket inserted between bracket and housing. A copper gasket having hole equal 
in area to that in the bracket must also be placed between the bracket and housing on the inlet side to 
keep cylinder alignment true. B. Gate valve. C. Webster Dirt Strainer. D. Webster Return Trap. 
E. Webster Bull's-eye Sight Glass 

190 




Fig. 17-3. Application of Webster Apparatus to paper machines where there are separate drips 

for each cylinder 

The housings of the machine and the brackets supporting the cyhnders 
are cored to provide ducts for conveying steam to the cyhnders and con- 
densation away from them. The frame on one side acts as a supply pipe 
while that on the other side acts as a return. Steam at a pressure of 15 
lb. per sq. in. or less is admitted to the housing and passes through the 



WEBSTER RETURN TRAP-, 




Union " \ WEBSTER DIRT STRAINER 

WEBSTER HEAVY OUTV TRAP 



Fig. 17-4. Application of the Webster System to a paper machine where there is a common return 
line for all cylinders with air removed separately from each cylinder 



191 



brackets and the journals to the cyhnders. To prevent collapse, vacuum 
breakers are installed in the cylinder heads, usually on the discharge end. 

Frequently it is advisable to make two or three separate steam supply 
connections to each housing, as the area of the cored opening in housing is 
too small to convey the required amount of steam without too great a pres- 
sure drop. 

The duct in the housing tlu-ough which the products of condensation 
pass can best be drained by the use of one or more Webster Heavy-duty 
Traps provided with thermostatically controlled air by-pass. 

Paper Machines: Two types of machines of particular interest are 
used in the manufacture of paper, cyhnder machines and Fourdrinier 
machines. Both require the evaporation of large quantities of water from 
the paper after the pvdp has been pressed and the web has formed. 

After passing through the presses the paper usually contains about 45 
per cent of water. This moisture is reduced to about 5 per cent, depending 
upon the thickness of sheet and the finish desired, by passing the paper 
over a series of drying cylinders, the inside surfaces of which are heated by 
either exhaust or live steam at low pressure or a combination of the two. 

Usually the steam-supply header 
runs parallel with the machine, close 
to the floor, a hole being bored in the 
header and connected by a pipe to the 
cored journal on the cylinder. 

The return header runs either 
above or below the steam header and 
has the same kind of connections as 
the supply. 

The drying cylinders vary in size 
and length. For the purpose of re- 
moving the water, one type of cylinder 
is equipped with buckets and another 
with what is termed a siphon pipe. 
Cylinders equipped with buckets dis- 
charge the condensation only when 
in motion, while those equipped with 




Fig. 17-5. Method of draining cylinder of a 
paper machine using Webster Return Trap and 
Webster Dirt Strainer. These connections are 
suitable for operation with either vacuum or gravity 
discharge 



siphon pipes discharge whenever water accumulates, provided there is suf- 
ficient pressure in the cylinder or vacuum in the return line to give the neces- 
sary difi'erential. 

The condensation per square foot of exposed drying surface of the 
cylinders depends upon the speed of operation and the thickness and width 
of the paper on the cylinders. The stock from which the paper is made, 
together with the amount of water extracted by the press rolls, also has a 
direct bearing upon steam consumption. The condensation will average 
about 13^2 lb- per sq. ft. of total roll surface and naturally is greatest at the 
wet end of the machine. 

The drainage from the cylinders may be removed either by gravity or 
by means of a vacuum pump, whichever is desirable. 

Usually with the Webster System of drainage, a Webster Return Trap 

192 





Fig. 17-6. Method of draining cylinder of a paper 
machine using Webster Heavy-duty Trap and Web- 
ster Dirt Strainer 



Fig. 17-7. Method of draining cylinder of paper 
machine for gravity discharge where a water line 
is to be maintained, using Webster Heavy-duty 
Trap with balanced steam connection, Webster 
Dirt Strainer and a Webster Return Trap for vent 
discharging into dry returns 



with its Webster Dirt Strainer and bypass is provided for each cyhnder as 
shown in Figures 17-3 and 17-5. All traps discharge into a main return 
which leads to the point of disposal, which is a feed-water heater or hotwell, 
open to the atmosphere for the removal of air. 

Webster , Heavy-duty Traps are sometimes used instead of Webster 
Return Traps (Figure 17-6) especially where the presence of a water line is 
desirable in the return (See Figure 17-7). 

The reader is referred to Page 184 for a complete discussion of the 
selection of the proper type of trap and the precaution which should be 
observed where thermostatic traps are used. 



193 



CHAPTER XVIII 



Application of the Webster System to Railroad 
Terminals and Steamship Piers 

THERE are many uses for thermostatically actuated return traps where 
the pressures carried are greater than in heating-system work. In- 
stances involving operation under steam gauge pressures of from 15 to 
100 lb. are described in this and following chapters. 

The requirement, in all cases, is that the return trap shall discharge 
the water and air of condensation without waste of steam and that the fix- 
ture being heated shall be maintained at maximum efficiency. 

In these special installations, certain fundamentals must be observed 
to secure successful operation. The first requires that the thermostatically 
actuated traps must discharge directly to the atmosphere or to a return line in 
which atmospheric pressure is maintained. 

This latter condition may be obtained by venting the return line free 
to the atmosphere. In some cases the same result is seciu-ed by discharging 
the returns into a flash tank, the vent of which is connected to the low-pres- 
sure heating main, while the condensation is cared for through the usual 
type of retiu-n traps to the vacuum return. 

Railroad Terminals — One of the greatest causes of delay in the daily 
movement of hundreds of trains into and out of terminals where there is 
freezing weather is the difficulty in keeping switches clear of snow and ice. 

Many terminals have therefore adopted the method (Figure 18-1) of 
placing steam-heating coils between the ties, under the switches. Due to 
the unusual exposure, these coils and their supply lines are operated under 
60 to 80-lb. gauge pressure in order to prevent freezing. The dripping of 

Main Steam Line 



Gate Valve 



t^^r^-fi 



^Nrf? 




WEBSTER HIGH PRESSURE 
SYLPHON TRAP 



Sheet Steel lastened' 
to Top and End of Ties 



Fig. 18-1. 



Ste9m coil arrangement for prevention of freezing of railroad switches 
194 



High Pressure 
Steam Line — 



Gale Valve - 



WEBSTER HIGH PRESSURE4> 
SYLPHON TRAP 



-Covering 



Stand Pipe 




Fig. 18-2. Method for prevention of freezing of fire protection 
lines. The water and steam pipes are encased in the same insula- 
tion and the steam pipe is drained by a thermostatic return trap 



these lines and coils pre- 
sents a double problem: 
First, water and air of con- 
densation must be freely 
discharged onto the road- 
bed, and Second, condensa- 
tion must not form steam 
clouds that might obscure 
nearby switch signals. 

A type of thermostat- 
ically actuated return trap 
which answers these re- 
quirements has been devel- 
oped by Warren Webster & 
Company after many tests 
and experiments. This re- 
turn trap is fitted with 
Monel-metal seats and valve 
pieces to withstand the wire- 
drawing effects of steam at 
high pressure differential. 
The thermostatic member 
is placed on the outboard 
or atmospheric side of the 
trap, and as the trap is 
generally placed in the rock ballast of the road bed, its exterior is usually 
given a special finish to give it protection against the elements. (See Page 275.) 
Railroad terminals are also equipped with extensive systems of water 
lines for fire protection purposes and these lines, too, must be kept from 
freezing. The method of prevention (Figure 18-2) found most satisfactory 
is to run a steam line, carrying from 60 to 80-lb. gauge pressure, parallel 
with and close enough to each water line that both steam and water lines 
can be encased in the same insulating covering. Where the water lines 
terminate, as at hydrant and hose gate outlets, the same dripping of the 
steam lines and the same thorough removal of condensation with absence of 
steam cloud are required as with the yard switches. 

The same type of return trap is used in both cases. 

Steamship Piers: Steamship piers in cold climates are somewhat 
similar to railroad terminals in that the Gre lines must be protected. In ad- 
dition, heat is required for a large number of small enclosures scattered 
tliroughout for housing the pier clerks. 

Piers are so built that water of condensation from coils heating water 
lines and clerk houses cannot be easily returned. The practice is to dis- 
charge the condensation overboard through the pier deck. The return traps 
must, therefore, keep the hues clear of condensation to avoid possibility of 
freezing and at the same time avoid waste of uncondensed steam. 

Webster Return Traps of similar construction to those previously 
described for railroad terminals are successfully used for this work. 

195 



CHAPTER XIX 

Applications of the Webster System to Vacuum 
Pans and Similar Apparatus 

IN processes of manufacture where boiling of the product at a low- 
temperature is desirable, a special application of the Webster System 
has been devised for removing air and water of condensation. 
One of the important uses for vacuum pans is in the milk-condensing 
industry and in the following pages this particular application of the Webster 
System is discussed. However, the principles and the Webster apparatus 
are equally applicable to other processes such, for instance, as the manu- 
facture of sugar, salt, candy or tartaric acid. 

The development and growth of the milk industry has reached a point 
in the last few years where it is now necessary, due to keen competition, to 
use not only the most modern and efficient machinery in the process of milk 
treatment, but to install modern power equipment and a perfect system 
of steam circulation in order to insure the commercial efficiency of the plant. 
It is essential that each pound of steam (live or exhaust) shall do the 
maximum of useful work and that all water of condensation shall be returned 
to the boiler. 

There are numerous uses for exhaust steam in the modern condensory, 
such as heating of boiler feed water, heating of water for general use and in 
the heating system of the building, but as a rule these require only a small 
portion of the amount of steam available from the exhausts of the engine, 
compressors, pumps, etc. 

In a condensory of say 100,000-lb. capacity of milk daily, there will be 
available at least 200 hp. of exhaust steam, not over 20 per cent of which is 
required for any of the above uses. The remaining 160 hp. of exhaust steam 
is available for use in the vacuum pans. 

The usual i^ractice in the past has been to use live steam in the heating 
coils of the vacuum pan at a pressure of about 15 to 20-lb. gauge, reducing 
to this pressure from the high-pressure mains. Very often excess exhaust 
steam from the engines has been wasted to the atmosphere, being considered 
a by-product of the engine room with little value excepting for its uses in the 
boiler room. Exhaust steam at 5-lb. gauge pressure contains about 88 per 
cent of the heat content of the live steam used to develop power and is as 
effective in the vacuum pan coils as live steam reduced to the same pressure. 
To make use of exhaust steam at 5-lb. gauge pressure where live steam 
was used in the vacuum-pan coils, only shght changes are necessary. Oc- 
casionally the sizes of coil connections must be increased to the size of the 
coils themselves and where the steam pressure is decreased, a slight addi- 
tional amount of heating surface in the coils will be required on account of 
the lower temperature of the steam at this pressure. In some plants where 
exhaust steam has been substituted for live steam without changes in the 

196 




Fig. 19-1. Milk condenser 



heating surfaces, a slight additional time was required to condense the batch 
of milk. In most cases this increase was not more than ten minutes. 

The usual control valve connections, that is, the double globe valve and 
a gauge attached to each coil connection, will be the same for use with the 
exhaust steam as with the live steam. 

The return connections for use with the exliaust steam are very simple. 
A single Webster High-differential Heavy-duty Trap (see page 249, Chapter 

197 



24), with a bypass, is connected to each coil outlet. These traps discharge 
to the return main leading to a vacuum pump in the boiler room. It is 
essential that each coil shall be drained separately into the vacuum return 
main in order that the pan operator may have absolute control of the steam 
pressure in each individual coil. 

It is necessary when condensing milk to vary the pressure in these coils 
at will. In some instances the pressure in certain coils must be reduced to 
atmosphere, while the pressure in other coils is increased to as much as 5 
lb. per square inch in order to cause a positive circulation of milk within the 
pan. Without this positive control of circulation it is impossible for the 
pan operator to properly manipulate the process. 

It is also imperative that the water and air of condensation shall be re- 
moved immediately from the coils of the vacuum pan and that this shall be 
accomplished independently of any conditions which may affect the opera- 
tion of the general exhaust steam system in the plant. 

It is advisable to use an independent pump and return line for the vacu- 
um pans and not to depend upon other similar equipment which may be 
used for heating the building. The return line should have a gradual gravity 
pitch to the vacuum pump and should be so arranged with by-passes and 
valves that in case the vacuum pump should become inoperative for any 
reason the return condensation may be discharged by gravity. There must 
necessarily be no pockets of any nature in this return line. 

A maintained vacuum of 6 to 8 in. at the outlet of the trap is usually 
sufficient to insure at all times a positive circulation of steam and the in- 
stant removal of all water and air of condensation. 

Not only are much better results obtained by the certainty of this cir- 
culation, but in many cases where exhaust steam has been substituted for 
live steam in the milk-condensing process, a marked improvement in flavor 
of the product has been noted. 

The great saving in steam consumption in a condensory when equipped 
with the Webster System will usually pay for the entire installation within 
a few months. However, a careful analysis must be made of the existing 
conditions of an old plant or the requirements of a new condensory before 
any exact arrangement can be determined. There is no other single im- 
provement to a condensory that will approach the saving obtainable through 
the economical use of exhaust steam. 

Figure 19-2 shows an older type of connection for vacuum pans, in 
which high-pressure steam only is used. The pressure is reduced from 
125-lb. per sq. in. boiler pressure to 15 or 20-lb.per sq. in. for use in the pan. 

The outlet connections are pipes without valves or checks, leading to a 
header which is piped to a tank located beneath the pan. The tank is a 
receptacle for water and air of condensation. The air is vented through 
the small vent valve while the water is drained to a high-pressure positive 
return trap which discharges the water to an open hotwell or to a feed- 
water heater. 

The difficulties encountered in this construction will be short-circuiting 
of the steam from one return to the other and the impossibility of maintain- 
ing independent or separate pressure control on each coil in the pan. 

198 



pressure reducing Valve 



-^r 




i 



Gauges 






^ 



By-pass- 



HiQh-pressure Main 




■Qt 




Vent Valve 



Positive Return Trap 

o 




To 8oiler Room 



Fig. 19-2. Drainage system for a vacuum pan using a positive return trap 
and receiving tank 



The system of piping, however, is in common use in most of the smaller 
condensories at the present time. 

Figure 19-3 shows another construction \Vhere the inlet connections are 
similar to those in Figure 19-2, but where the outlet connections are con- 
trolled by means of gate valves and check valves which discharge into a 
common return hue. This return line is run direct to a pump and receiver 
which discharges the water back to the boiler. A great many installations 
are somewhat similar to this and it is evident that there is a great deal of 



199 



waste of steam due to the inability of the operator to properly throttle the 
controlling valves on the outlet connections. 

Figure 19-1 shows the approved application of the Webster System. 

The exliaust-steam piping includes a Webster Steam and Oil Separator 
and an auxiliary connection from the high-pressure main with pressure- 
reducing valve. It is essential that the pressure-reducing valve shall be of 
such construction that it will maintain constantly the pressure which is de- 
sired when it is necessary to use live steam for condensing. The back- 
pressure valve must be of such construction that it is impossible at any time 
to exceed 10 lb. per sq. in. pressure on the low-pressure mains. 

The outlet connections from the vacuum pan are run direct to the 



Pressure- reducing Valve 




ir—ir 



Fig. 19-3. Drainage system for a vacuum pan using a pump and recei\er 

200 



Exhaust Head 




Return to Vacuum Pump "rip lo Waste 

Fig. 19-4. Approved manner of applying the Webster System to a vacuum pan 

Webster High-differential Heavy-duty Traps, which are provided with by- 
passes and thermostatically controlled air lines and are connected directly 
to the vacuum return line, which is run through a Webster Suction Strainer 
to the vacuum pump. These outlet connections also must be equipped with 
small try-cocks in order that the operator may test the working condition 
of any coil in the pan at any time. 



201 



CHAPTER XX 



Application of the Webster System to Sterilizers, 
Cooking Kettles and Similar Apparatus 

HOSPITAL Equipment: All hospital equipment, such as sterilizers for 
surgical instruments, bandages and dressings, blanket warmers, etc., 
requires steam at more than the usual heating pressures. As these 
fixtures are comparatively small consumers of steam, being operated at gauge 
pressures of 15 to 100 lb., and as they are situated at different parts of 
the building, it is usual to run a special set of steam supply and return lines 
for them so that steam may be available at any time throughout the year. 
For the purpose of insuring rapid removal of condensation and air from 
each fixture, a Webster Return Trap of similar construction to those 
described in the preceding chapter is placed on the return of each unit. The 
operating temperature of the thermostatic members of these traps is close 
to that of steam at atmospheric pressure; hence it is necessary to provide 
sufficient exposed piping between the fixture and the trap to allow the con- 
densation to cool down to the operating temperature of the return trap. 
This exposed piping is termed cooling surface. 



Dressing Sterilizer 



Blanliet Warmer Closet 




Gate Valves 

To Waste or Atmosphere 
'Dirt Pocl<et 
WEBSTER HEAVY DUTY TRAP 

Fig. 20-1. Application of the Webster System to instrument sterilizer, dressing sterilizer and blanket 

warmer closet in a hospital 

202 



Vent tu Heat Main 
"or Atmosphere 




Outlet Connection 
from Apparatus 
to tie Dripped 



Union 




WEBSTER HIGH-PRESSURE 
SYLPHON TRAP 

Fig. 20-3. Connections for return trap 
^ High Pressure Trap '*^ ' where the operating pressure exceeds 10 lb. 

per sq. in. 

Fig. 20-2. Method of discharging high-pres- 
sure drips or returns from high-pressure apparatus 
into low-pressure heating mains and vacuum return 
mains through a Webster Heavy-duty Trap 

Each return from trap before connecting into the common discharge 
hne of similar traps should have a check valve between the trap and the 
return as well as a hand shut-off valve between fixture and trap as shown in 
Figures 20-3 and 20-4. This is very important as a protection for the trap 
against water hammer. 

Where several Webster High-pressure Sylphon Traps discharge their 
condensation into a common return line, it is necessary that this line 
shall be vented free to the atmosphere, or in cases where possible, to 
the low-pressure heat main (Figure 20-2). It is important that no back 
pressure shall be carried on this return line. In no case should the discharge 
of these traps be connected directly to a vacuum return as the vacuum 

Coffee Urns 




Vent to Low Pressure Heat ^^^^'^ ^^'™^ 

Main or Atmosphere 



Gale Valves 



Check Valves 




Gate Valves 
-To Waste or Atmosphere 
- Dirt Pocket 
To Return ^ebSTER HUVY DUTY TRAP 

Fig. 20-t. Application of the Webster System to kitchen equipment 

203 



would unbalance the operating member of the trap and cause it to give 
unsatisfactory results. 

Cooking Kettles, Plate Warmers, Bain-maries, Coffee Urns 
AND Other Kitchen Equipment: This equipment requires practically 
the same treatment as that of hospitals, and the same general statement 
about arrangement of return lines applies. 

In food-product factories where the cooking equipment is much more 
extensive, a special form of float-controlled return trap with thermostatic 
trap in air line is used. This particular type is called the Webster High- 
differential Heavy-duty Trap. For details of these traps see Chapter 24, 
page 249. These traps are also used for removing the condensation and 
air from the steam coils of vacuum pans in evaporating processes for 
sugar, milk, salt, tartaric acid, candy, and the like. 

// is important in all applications to high-pressure duty that the maximum 
initial steam pressure to which the trap may be subjected does not exceed the 
allowable pressure of that class {see Page 275), and that the maximum conden- 
sation rate shall be known. It is also important to know in advance the lowest 
pressure to which the vent of the Heavy-duty Trap ivill be subjected at times, as 
the influence of this pressure is marked in limiting the rating of the Webster 
High-pressure Sylphon Trap. 



201 



CHAPTER XXI 

Applications of Webster Systems to Greenhouses 

THE heating of greenhouses is a special field, owing to the peculiar 
characteristics of the buildings and the necessity for uniform interior 
temperatures. 

Commercial greenhouses are more exacting in their heat requirements 
than are public or private conservatories. Constant maintenance of the 
most desirable temperatures is essential in commercial houses to bring the 
crop to salable maturity in the shortest possible time and to keep the quan- 
tity of first-class product at a maximum throughout the season. A single 
serious temperature drop for a comparatively short interval may stunt the 
crop beyond recovery to normal condition within a months time, and even 
slight temperature variation renders some kinds of plants more susceptible 
to certain destructive fungi. 

The heat regulation should be flexible to such extent that by applying 
more or less heat to compensate for loss of sunlight in cloudy weather, the 
crop can be retarded or forced to reach maturity at the time of the most 
profitable market. The blossoming of Easter lilies, for instance, requires 
absolute regulation within a period of a very few days, and failure to 
meet the time limits results in an almost total loss. The same principle is 
utilized during the period of uncertain sunshine between November and 
February to keep the daily production of the majority of varieties of cut 
flowers more uniform. 




Fig. 21-1. Conservatory of the Missouri Botanical Gardens 

2n.> 



Owing to the high rate of heat transmission through the glass of which 
greenhouse enclosures are constructed, the heating system must be capable of 
quick response to the demands for extra heat during nights, cloudy and cold 
days, and particularly when a sudden cold wind springs up. Co-operating 
with the ventilators, the heating system must respond quickly to the 
demand for less artificial heat, when the heat from the sun's rays tends to 
increase the interior temperature beyond the point desired. 

Until a few years ago, hot water was con- 
sidered the best medium for circulation in the 
heating coils of greenhouses. However, as the 
size and importance of greenhouses have in- 
creased, a medium with quicker response in 
heat flow has become necessary to better meet 
the many changes in outside temperature and 
direction and velocity of wind. Steam has 
proved ideal for this work where the condi- 
tions of the individual problem have been 
carefully analyzed and a suitable heating lay- 
out has been applied. 

In different types of greenhouses the ar- 
rangement of the heating coils varies to suit the 
particular plants or vegetables grown and to 
meet the needs of forcing, propagation, etc. 
The conservatory group of the Missouri 
; "eTch Botanical Garden at St. Louis, Mo., consisting 
of palm, economic, cycad, succulent and fern 
houses (Figures 21-1 to 21-5), is heated by the 
Webster Vacuum System of Steam Heating. 
These greenhouses are part of the 125-acre 
botanical garden presented to the public 




Fig. 21-2. Plan of half the Conservatory of the Missouri Botanical Gar<lens, showing layout of heatmg coils 

206 



by Mr. Henry Shaw at his death in 1889. 
Eleven thousand species of plants 
grow in this garden. The palm house 
contains 150 kinds of palms, such as date, 
cocoanut, sugar, Panama and rattan. The 
economic house has a variety of tropical 
and sub-tropical plants, such as rubber, 
spices, drugs, dyes and coffee. The cycad 
house is arranged in Japanese style and 
contains representatives of all known 




Fig. 21-3. Elevation of half of houses A and B (see Fig. 21-2), Conservatory, Missouri Botanical Gardens. 
Other halves of these houses are symmetrical with the parts shown 



207 




Fig. 21-4. Fern House of the Missouri Botanical Gardens 




Fig. 21-5. Floral Display House of the Missouri Botanical Gardens during chrysanthemum show 
The accurate temperature regulation obtainable with the Webster System greatly lengthens the 
prime life of the individual blossoms, thereby assisting in prolonging the duration of the show 

208 



genera of cj^cads, as well as a collection of tropical evergreens. The succulent 
house contains species of all the plants found in the deserts of the world. 
The fern house has a very complete collection of the numerous ferns and 
their allies. 

Different atmospheric conditions are required in each of these houses. 
Ferns, for instance, would not live in the dry air needed by the cacti. The 
Webster System is maintaining the required temperatures throughout every 
part of these conservatories, and in most locations the permissible variation 
in temperature is limited to five degrees. 

The palm house is 60 ft. high. To assure maintenance of tempera- 
ture within 5 deg. variation, the sizing, locating and controlling of radiating 
surfaces were specially important problems of the design. 




/// 




X / 


/ 


' x^ 




/^'y 





Fig. 21-6. Typical temperature chart from one of the greenhouses of the Davis Gardens, Terre Haute, Intl. 

The outside temperature on the day the chart was taken averaged 28 deg. fahr. The variation 

in inside temperature was less than 3 deg. in 24 hours 

209 




Fig. 21-7. One of the ten 600 by 80-ft. greenhouses of the Davis Gardens, Terre Haute, Ind. 
In the trade, this establishment is looked upon as a leader in quality of product as well as capacity. 
The ability to force or retard the crop in each greenhouse assists materially in regulating the output to 
best meet demand, and in this respect the Webster Vacuum System plays an important part. 




Fig. 21-8. Crosswise view at the center of one of the cucumber houses of the Davis Gardens, 
showing arrangement of heating coils around the beds 

210 




Fig. 21-9. Part of the power plant of the Davis Gardens, showing the feed-water heulur and 
vacuum pumps of the Webster Heating System 

The heating coils are banked on the side walls of the houses as shown 
in Figure 21-3, and the arrangement of the coils is shown in plan, Figure 
21-2. Steam is supplied from a central heating plant under pressure and is 
reduced at the conservatory, the heating system operating at from 1 to 
2-lb. gauge pressure. The returns flow to the power house, where the main 
vacuum pumps discharge the condensation to an open tank, from which it 
is pumped to the boilers. 

The J. W. Davis Company of Terre Haute, Indiana, operates the 
largest hothouse vegetable growing plant in the country, this plant con- 
sisting of 10 greenhouses, each 600 ft. long by 80 ft. wide and one green- 
house, 200 ft. long by 20 ft. wide. Some idea of the magnitude of these 
houses may be obtained from the fact that for heating alone an 1800-hp. 
steam generating plant and 60 miles of coils and piping are required. 

The main vegetables gro^\'n by the Da^'is Company are hothouse- 
grown cucumbers, tomatoes and mushrooms. The average output is as 
follows: cucumbers, 12000 dozen per week; tomatoes, 40000 pounds per 

211 




■a 
c 

V 

c . 
ft- 2 
-a .c 

a^ 

"-" u> 

o .5 

s ^ 

r3 .613 
— 'w 
5 ^ 

So 



o •" 



3 -o 

O 
I - 



o 

T 

(N 

si: 

E 



212 




Fig. 21-11. View across Orangerie, du Pont Horticultural Group, Mendenhall, Pa 







Fig. 21-12. Method of heating for growing vines on the walls of the duPont orangerie. Air enters the 
openings at the bottom of the wall, is heated in passing over the coils at the top and passes into the 
rooms. The registers in the floor distribute heated air from the indirect heating system 

213 



week; muslirooms. 2000 pounds per week. The output includes also flower- 
ing plants, among which are hundreds of thousands of cyclamen, grown for 
the sale of cut flowers as well as the plants themselves. 

The temperature requirements of these greenhouses are even more 
exacting than those of the Missouri Botanical Garden, as shown by the 
chart. Figure 21-6, taken from the recording thermometer. 

The steam for heating is taken from a 95-lb. steam hne running through 
the connecting corridors, and the pressure is reduced in each greenhouse for 
the Webster Vacuum Heating System, which operates at 5-lb. pressure. 
The condensation is carried through a vacuum return back to the power 
plant, where it is delivered by the main vacuum pumps through a tank to 
a Webster Feed-water Heater and from there pumped to the boilers. 

The Horticultural Group (Figure 21-10) on the private estate of Mr. 
Pierre S. du Pont near Mendenhall Pa., is heated by the Webster System. 

The main buildings comprise the orangerie, exhibition hall, peach 
houses and display houses. The orangerie is approximately 80 by 180 ft. 
and the exhibition hall is about 80 by 110 ft. The two peach houses lie on 
either side of the orangerie and are approximately 50 by 100 ft. in length, 
with the display house 30 by 50 ft. at the extreme ends. At the rear of 
the Exhibition Hall is a stage, or rather a veranda, to the future building, 
which will eventually be the casino. At this end of the building are located 
the organ and service rooms for entertaining purposes. 

The heating for this group is remarkable in that the main buildings 
are heated by a system of indirect radiation with a gravity circulation of air, 
The indirect surfaces enclosed with copper casings and pans, are placed in 
a series of tunnels which lie under the walk-ways. Fresh air when required 
is taken through two sets of primary heaters located in the orangerie and 
one set of primary heaters for each of the peach and display -house wings. 
These are furnished with sufficient surface to maintain the air in the tunnels 
at 60 deg. fahr. 



214 



CHAPTER XXII 



M' 



Installation Details 

"ANY of the methods of pipe connections which have been developed 
by Warren Webster & Company during the past 34 years, and 
have become standard practice, are shown in this chapter and 
elsewhere in connection with descriptions of specific apparatus. Most 
of the illustrations have been published as Webster Service Details and are 
familiar to the profession and trade. These drawings, which indicate the 
general arrangement of the pipe, fittings and Webster apparatus have 
been revised from time to time and, as shown here, represent the latest and 
best thought. They are not to be used for exact layouts of piping, as each 
individual application presents its own special conditions. No effort has 
been made to indicate the necessary unions or right and left nipples required 
for the connections, as these requirements for any case would naturally 
be best determined by the detail of the layout or by the steamfitter at the 
job, based upon his skill and upon materials available. 



Details Applicable to Both the Webster Vacuum System 
and the Webster Modulation System 



Rise to new level 





-Rise to new level 



WEBSTER CLASS"B' 
DIRT STRAINER, 
Reducing Gate Valve 



Provide at least 3-0 
' pipe cooling surfaci 
between drip point and 

return trap Connect into lop 

or side of return main 



WEBSTER CLASS "B" 
DIRT STRAINER 
Reducing 




Fig. 22-1. Application of a ^^'ebste^ Return Trap 
on a low-pressure heat main, at a low point where 
the main rises. A suflicient length of uncovered pipe 
must be provirled between the drip point and the 
return trap 



Gate Valve 

_WEBSTER HEAVY DUTY TRAP- 

Set trap on bracket support ^ 

on foundation or on Hoot-'' Connect into 
top or side ol 
return main 



Fig. 22-2. The drainage of a low-pressure heat 
main at a low point, where the line rises, is of such 
importance that special attention is warranted. 
This diagram shows a large main with drip through 
gate valve, Webster Dirt Strainer and Webster 
Hea\'y-duty Trap 



215 



Live Steam Irom Boiler 

\ 
JL 



By-pass with Globe or Angle Valve 



WEBSTER 
WATER ACCUMULATOR -v 



Tee for Gauge Connection 




Straight Pattern Pressure 
Reducing Valv) 

Fig. 22-3. Connections for a steam pressure-reducing valve. The control pipe from the low-pressure 
side of the line must be taken from a point far enough from the valve to insure that the pressure will have 
been fully expanded. The use of the Webster Water Accuramulator (see Page 267) facilitates a constant 
static pressure on the diaphragm of the pressure-reducing valve. The pop safety valve prevents pressure 

building up, particularly at very light loads 
Return Riser 





ucer— -"W 



1 J4 Pipe uncovered-"* 



Gate Valve ~; 



Dirt Pocliet- 








WEBSTER 
RETURN TRAP 



Plug 



Fig. 22-4. Method of dripping supply risers Fig. 22-5. Three methods of making loops to 
through a Webster Return Trap into vacuum return provide for expansion movement in risers. The ex- 
line; the vertical leg acts both as cooling surface and pansion of supply and return risers should have 
dirt pocket careful study 



Up to Radiator 




Dirt Pocliel— _J_4 



_ Fig. 22-7. Arrangement for drip- 
ping a down-feed riser into an over- 
head return main, showing the un- 
covered horizontal cooling pipe 



' Supply Riser 




Fig. 22-6. Arrangement 
for dripping the end of a sup- 
ply main, which also carries 
the condensation from the up- 
feed risers, into an overhead 
return main. The return trap 
is located at a point four 
feet or more from the point 
dripped 



WEBSTER 
RETURN TRAP 



Overtiead Return IWaJn-^ 
216 



irt Pocl<et-__J — \ 



Fig. 22-8. Dripping the 
heel of a down-feed supply 
riser, where provision must 
also be made for down thrust 
or expansion. The horizontal 
pipe must pitch sharply 
enough to prevent formation 
of pocket when the riser is 
fully expanded 



^/Floor Line S. 




Up to Radiator-^rq 



Pl; ^Supply Riser 




Gate Valve 



Floor Line 



Return Main at Floor 



I <t 




Fig. 22-9. The end of an 
up-feed system supply main 
where provision must be 
made for the drip of the main 
as well as the condensation 
from the risers. The return 
is located along the floor and 
the vertical line to return trap 
can be used as a cooling leg 



WEBSTER RETURN TRAP 



Fig. 22-10. Arrangement for drip- 
ping down-feed risers into an overhead 
return line. Cooling pipe used with a 
Webster Dirt Strainer located at the 
entrance to the return trap. The hori- 
zontal pipe must pitch sharply down- 
ward to prevent formation of pocket 



r^ — Supply Riser 




WEBSTER 
DIRT STRAINER 

WEBSTER 
RETURN TRAP 



£3<- Up to Radiator r°\<- — Supply Riser 




Fig. 22-11. Arrange- 
ment for dripping the end 
of an overhead supply 
main through Webster 
„. Dirt Strainer and Return 

RETURN TRAP Trap into an overhead re- 
turn main 



217 




Fig. 22-12. The drip of the end of a 
branch supply main which also carries 
the drip of down-feed risers. A Web- 
ster Dirt Strainer is used in place of a 
dirt pocket 



fi- |<3 Return Riser yifEBSTER MODULATION VALVE 
^Supply Riser gushing 




Fig. 22-1.3. Showing provision 
for expansion on a down-feed 
riser and the method of dripping 
through Webster Dirt Strainer 
and Return Trap. Pitch hori- 
zontal pipe downward sharply to 
prevent formation of pocket 

i.' Return Main at Floor 



WEBSTER 
DIRT STRAINER 



WEBSTER 
RETURN TRAP 



Fig. 22-11. Arrangement of 
connections to a hot- water type 
radiator where the branch run- 
outs are in the floor construction 



Return Riser 




Fig. 22-15. Arrangement of connections to a steam-type radiator where the branch run-outs 

are in the floor construction 

218 



Heating 
Riser—; 



^^ci^ 



c-None of the Piping shown 
on this detail to be covered 




Connect to Return 



Fig. 22-16. In certain classes of buildings a small 
amount of heating surface is often desired in bath 
rooms, etc., without involving the expense of sep- 
arate radiators. Where these rooms are one above 
the other a heating riser may be used with connec- 
tions as shown in this diagram 



Supply Riser 




Reducer 



'Uncovered 
Pipe 



Gate Valve 




Return Main 



Fig. 22-17. The dripping of the end of an over- 
head steam supply main where the return line is 
carried along near the floor. The uncovered ver- 
tical line to the return trap acts as a cooling leg 



Supply Riser 



WEBSTER MODUUTION VALVE 
/ Bushing 



Returns* 
Riser 



Return Riser 
Supply Riser 

^WEBSTER MODUUTION VALVE 
ushing 




Fig. 22-18. Arrangement of connections to a 
radiator in a factory or loft building where there is 
no objection to branch run-outs on the ceiling of the 
floor below 



Fig. 22-19. Arrangement of connections to a 
radiator with aU branch run-outs exposed in the 



219 



Supply Riser- 




Fig. 22-20 Arrangement for removing a considerable amount of condensation from a down-feed riser. 
The drip goes through a Webster Dirt Strainer and Return Trap, the connection to lowest radiator being 
made above the drip point. Fig. 24-23, page 253, shows an alternate method using a Webster Double- 
service Valve 



t Manilold Coil 



Above IWelhod lor Coils 
ol not over 10 Pipes 

I'z' Short Nipple 
Reducing Tee 

_, Dirt Pocket 

1', 2' Nipple, 6"long 



^Manilold Coil 




Above Method lor Coils 
ol 1 I Pipes or over 

ll'2 Short Nipple 
Reducing Tee 
,, Dirt Pocket 
IV2 Nipple, 6"lonD 

Fig. 22-21. Drip connections to the return head- 
ers of manifold coils. Coils of ten pipes or less have 
one return header and those of over ten pipes are 
usually split and provided with two headers. Fig. 
24-23, page 253, shows an alternate method using a 
Webster Double-service Valve 



Connect into Top 
of Vacuum Return 



Fig. 22-22. Arrangement of headers similar to 
Fig. 22-21, but showing the use of the Webster Dirt 
Strainer at the entrance of the return traps 



220 



pca Pn r-c 



Dirt Pocket 'ir! 




xBotlom Outlet ManKold 



WEBSTER RETURN TRAP 



■Connect into returr 
y main ot riser 



PLAN 



BOTTOM OUTLET MANIFOLD 



^^J^_^!_^L^_^^/ Bottom Outlet Manifold 




^WEBSTER 
' DIRT STRAINER ^ 
PLAN 
BOTTOM OUTLET MANIFOLD 




WEBSTER RETUitN 
TRAP 



Connect into return 
main or riser 



Nipple, maximum size 



Nipple, maximum size 



.Reducing E!t, 
"^bustled If necessary 



ELEVATION 
END OUTLET MANIFOLD 

Drop l.efl- 




_ Reducing Ell. 
bushed il necessary 

I WEBSTER ^fBsTfB 

J,DIRT STRAINER „««f,ER^, 



ELEVATION 
END OUTLET MANIFOLD 



Corinect Into return 
main or riser 




Fig. 22-23. With drop leg to catch dirt 



Fig. 22-24. With Webster Dirt Strainer 



Return connection to a flat overhead coil where (above) a bottom-outlet manifold and where (below) 
an end-outlet manifold is used. Dirt is collected by drop leg (Fig. 22-23) or by a Webster Dirt Strainer 

(Fig. 22-24) 



Manifold 
'Coil 




WEBSTER RETURN TRAP— j'i,^JP=91l~Gale Valve 
^Drop Leg 



Connect to 
Vacuum Return 



Fig. 22-25. With drop leg to catch dirt 



Reducing 
Ell 



r-a c-1 r-Q p-i rci f7^ P^ r^ p~\ r<t p* 



Manifold 
Coil 



Reducing 
Ell . 




Gate Valve ^( 



„_^-V»EBSTER CUSS "B" 
Connect to T_/ dirt STRAINER 
Vacuum Return 



0).-WEBSTER RETURN TRAP 



© O O' ©' ©' © ©ijsQ'Q't} 





Fig. 22-26. With Webster Dirt Strainer 



Wide flat overhead coils should have return connections taken from both ends of the return manifold. 
Dirt is collected by a drop leg (Fig. 22-25) or by a Webster Dirt Strainer (Fig. 22-25) 



221 



Fig. 22-27. Arrangement for profitable use of the heat 
in the condensation from a heating system. The conden- 
sation is passed through the coils of an auxiliary water 
heater and its heat is transferred to water for domestic or 
manufacturing use 



Note — Additional details applicable 
to the Webster Modulation 
System will be found on 
pages 228 to 232 




Details Applicable to the Webster Vacuum System Only 




Exhaust Inlel 



Mow 



n n 



Fig. 22-28. Under certain conditions the condensation from the heels of down- 
feed risers can be removed by connecting the separate gra\dty drip or wcl-return line 
to the return inlet of a Webster Feed-water Heater. In this instance, the static head 
between the top of the heater and the lowest radiator connection must exceed the 
pressure in the heater. Suitable connection of the return Une to the heater is shown 
in the diagram 

090 



^Return Riser- 




Fig. 22-29. Where the drips of risers and mains are carried through a separate gravity drip 
line near the floor and it is desired to deliver the condensation into an overhead vacuum return 
line through a Webster Heavy-duty Trap, tiie arrangement shown has proved most satisfactory 



-Return Riser 
'Supply Riser^ 

Union 



-Return Riser — 
Supply Risej^ 



Gate Valve 



D"""" Overhead Vacuum Return 

NHfltO WEBSTER LIFT FITTING ^n> I 




Floor Line 



Fig. 22-30. In the usual down-feed system where the drips of risers are cared for by a separate 
gravity drip line run near the floor and where the condensation is to be delivered to an overhead 
vacuum return line through a Webster Heavy-duty Trap, the method shown should be followed 

223 



Supply Riser - 



=h^-— 'Return Risei 



Gate Valve - 



^ 



t,: _ J 



Reducer- 



Pipe uncovered. 



Gate Valve - 



w 



Dirt Pocket 

Cap — > rm 



^Ceiling 



-One size larger than Trap 




-WEBSTER RETURN TRAP 



Z^— ""'"a 



P~ 




o 



Steam Supply Main 



Return Main 



Fig. 22-31. Arrangement for drip- 
ping both riser and main where an up- 
feed riser is fed from the bottom of a 
supply main. A vertical cooling leg is 
used 



Ceiling 



Steam Supply Main 



Return Main 



Fig. 22-32. Arrangement of connec- 
tions where the up-feed riser is fed from 
the top of the overhead supply main 
and the return main is also overhead. 
A vertical cooUng leg is used 



Supply Riser 




WEBSTER RETURN TRAP 

Plug 



Floor Line 



Dirt Pocket 
Cap 



Ceiling/ 
WEBSTER RETURfl TRAP 



Return Main 



Return Riser 



,'Supply Riser 




Dirt Pocket 
Cap 



Fig. 22-33. Where it is not possible to run a vertical cooling leg on the drip of the riser, cooling surface 
in the form of a horizontal pipe may be employed as shown 

224 



Fig. 22-34. Arrangement for removal of 
condensation from a group of not over 14 
sections of vento radiation, where the steam 
supply enters one end of the group and the 
returns are taken from the opposite end. 
The return of each group is separate, the con- 
densation being carried through a common 
return line to the Webster Heavy-duty Trap, 
and the airfromeach group 
handled separately 
through a Webster Re- 
turn Trap connecting to 
a common discharge line 
to the vacuum return line. 
For details of the Webster 
Heavy-duty Trap see Fig- 



Blast Heater Sections 



ure 22-35 



WEBSTER RETURN TRAPS 




Vacuum Air Line 



Gate Valve 

VIEBSTER DIRT STRAINER 

WEBSTER HEAVY DUTY TRAP' 




Thermostatically Controlled 
Air Bypass 




Fig. 22-35. Cross section of Webster Heavy-duty Trap with thermostatically controlled air by-pass, 

to prevent trap from becoming air-bound 



225 



Fig. 22-36. The usual method for removal of con- 
densation from a group of not over 22 sections of 
vento radiation supplied with steam at each end, is to 
provide a drip connection also at each end as shown. 
In some instances, however, where the pressure is low 
or more than 22 vento sections are used, one of the 

return Unas should be extended 
Co„^";'Zs' through the Vento bushing and 

to about the center ot the group, 

so that air-binding will be 

avoided 

Blast Heater Sections 



WEBSTER .RETURN TRAPS 



Drip Connections 
same as stiown 
for opposite Side 




- Blast Heater Sections 



Gate Valve- 
WEBSTER DIRT STRAINER > 



Ecce 
Bushing 



niric .dPCj^ WEBSTER RETURN TRAP 




WEBSTER HEAVY DUTY TRAP 



Fig. 22-37. Method of dripping 
double-tierj blast heater sections 
through Webster Dirt Strainer and 
Hea\ y-duty Trap 

WEBSTER RETURN TRAP 



Vacuum Air Line 



Ife- 



WEBSTER 
HEAVY-DUTY TRAP 



±=^ 



Check Valve 



& 



WEBSTER DIRT STRAINER' 



-..Aiy ^tttt^ 



Vacuum 
Return 



226 




Return Main 



WEBSTER RETURN TRAP 



Fig. 22-38. Drip of main and up-feed riser using horizontal cooling surface 



Supply Steam 
Connections 



Blast Heater Sections 





Eccentric Bushings 



WEBSTER DIRT 
STRAINER 

WEBSTER 
HETUHN 
^TRAPS 



A 



-Doorway — 



Air Pipe 



Air Pipe must be 
'/a Diameter ol Return 



Return toward 
Vacuum Pump 



Vacuum Return 
Near Floor" 



'/2 Difference 
I in Levels 

J 



t 



r 



Floor Line 



Plugged Tee. 



T^^^^^^^^^^ 




Line of Trench 
Under Doorway 



Plugged Tee 



Hot Water Outlet 
HotWatci Generator 
Steam Inlet 




Vacuum Return 



Fig. 22-39. Arrangement of piping where 
a vacuum return line is carried along the wall 
near the floor and passes doorways or other 
openings. The water is carried under the 
opening and the air is passed through the 
line over the opening 



Fig. 22-40. Method of dripping blast heater section through 
Webster Return Traps 



Reducing Ell 



Gale Valve 

/ 



WEBSTER HEAVY-DUTY TRAP 



^Mud Blow 



WEBSTER CLASS B" DIRT STRAINER 




Fig. 22-41. The approved 
method of draining condensation 
from the c o i 1 s of a hot-water 
service heater to the vacuum 
return line through gate valve, 
Webster Dirt Strainer and 
Webster Heavy-duty Trap 



Trap on Bracket Support 
on Foundation or on Floor 



227 



Details Applicable to the Webster Modulation System Only 



Supply Riser or 
Supply Connection 
to Radiator 




This Connection '/2 when Air Line Valve is 
10' O'or less from Dry Return Branch or 
Main and 3/4 when over 10'0"distant / 



CeiInQ Line"" 
1/2" WEBSTER RETURN TRAP^ 

1/2 Socket 



Supply Mam must be 
Run Full Size to Drip 
Point Connection 



Drop Leg- 




First Floor Line " 




Drip to Wet 
Return at end . 
of Run in Main 



Reducing Tee 



Union above 
Water Line 
of Boiler 



Water Line ot Boiler^ 



Overhead Djy Return/ 



Under no Circumstances must the 
Center Line of this Pipe be less than 
6" above Center Line of Return Inlet 
of Vent Trap 



^Never less than 1" 
— ^Reducing Tee 



Connect into Wet- 
Return Main 



Union above Water Line of Boiler 



q=rr- 



/Water Line of Boiler 



Connection into Wet Return Line - 



Wet Return near Floor 
Nv- 



Wet Return near FIooj;, 
with space beneath tor 
Cleaning 



The Connection into Wet Return 
must be same size as Dry Return 
before Rise is made 



This Connection must be on same 
Centre as Wet Return 



Special Swing Check Valve 



L 



Floor Linei '-^ 



i=^ 



2 



'Floor Line 




Fig. 22-43. Where a drip is required, at 
the end of a heating main, the air should 
usually be vented through a Webster Re- 
turn Trap into the dry return, as shown 
in this diagram 



Fig. 22-42. The dry return in a Webster Modulation 
System, due to its required grade, must sometimes get 
down into the head room, in which event it may be 
drained into the wet return and elevated to a higher 
level. Certain fundamentals must be observed in do- 
ing this. The most important is that at the point 
where the change in elevation occurs, the dry return 
must never be closer than 6 in. to the level of the 
inlet to the Webster Modulation Vent Trap 



228 



WEBSTER RETURN TRAP 
Above highest point of — 
Dry Return 



Supply Main 




30 or more If possible 



Union— '<1-'t' 



This Connection must Special Swlna 
be on same Centre as ^^ Check Valve 
Wet Return ^"^\ \ 



Fig. 22-44. There is 
often a demand for hot 
water for domestic sup- 
ply where this water 
can best be heated by 
transfer of part of the 
heat from the conden- 
sation in the steam 
heating system. The 
diagram shows one method of doing this in connec- 
tion with a Webster Modulation System. The hot- 
water heater and storage tank should be located close 
to the stCEun boiler so that the steam supply will be 
available when the plant is being operated at very 
low pressures 



Water Line of Boiler^ 



'Return from ftot Water Generator. Connect to Wet Return 



Wet Return near Floor 



g pMH^ 



X_ 



Floor Line -a 



WEBSTER RETURN TRAP 




Fig. 22-45. Connections for overhead radia- 
tion in basement, where there is sufficient drop 
for gravity flow between the radiation and the 
water line of the boiler 



Connect into 
Wet Return Main" 



Water Line of Boiler- 



tjPNP 



Special Swing Check Valve 
-This Connection must be on same 
center as Wet Return 



Wei Return near Floor 



229 



V'l"Pipe Sleeve over Rod must — >\\ 
extend thru Bolt Holes in Diaphram' 
Portion ol Damper Regulator 



WEBSTER MODULATION VENT TRAP 



Overiiead Return from 
Heating System 



Fig. 22-46. Typical ap- 
plication of Webster 
Damper Regulator 
Check Valve to a cast-iron sec- 

tional boiler 




Fig. 22-47. Method of making connections to boilers operating in parallel. Check valve on vent dis- 
charge trap only. This is the arrangement of return connections required by 
many boiler insurance companies 



230 



WEBSTER 
MODULATION VENT TRAP 




Overhead Return 
from Heating System 



This Distance to „ 
be not less than 30 



Water Line,of Boilerj 



Drip from Bottom 
_of Steam Header 
to connect to Return 

Header of Boiler 



With thermostatic control 



Lock 



V2flod Threaded at ends wiih^j 

3/4ptpe Sleeve over Rod must 

extend through Bolt Holes in 

Diaphragm Portion of Dami 

Regulator. 

Remove Pin from Damper^ 

Regulator. 



WEBSTER I 
MODUUTION-- 
SYSTEM GAUGE 




Overhead Return 
from Heating System 



This Distaince to be 
not less than 30' 



Water Line of,, Boiler; 



Drip from Bottom 

of Steam Header 

to Connect to Return 

Header of Boiler 



Note:- 

Oamper Regulator Lever to Rest on 

Knife Edge in Slot of Damper Regulator 



With time-clock Control 



Fig. 22-48. Typical applications of special controlling devices which may be applied to 

Webster Damper Regulators 

231 



WEBSTER RETURN 
TRAP, above Highest 
Point ol Dry Return 



.Conned into Top of Return .Supply Line 



Fig. 22-19. Radiation must sometimes 
be placed on the side walls of basements, 
where steam can be circulated only by pro- 
viding sufficient head for gravity flow be- 
tween the radiator return outlet and the 
water line of the boiler. The arrangement 
shown handles this problem well 




Ttiis Connection must 
be on same Center as 
Wet Return 

\ Special Swing 
Check ValveS, 



^fW 



Water Line of Boiler 



Return Iron Radiator 
Connect to Wet Return 



Wet Return near Floo 



l^i_ 



Fluor Line"^^ 



232 



CHAPTER XXIII 

Capacities and Ratings of Webster Valves 

and Traps 

CAPACITY is a basis obtained from tests under one set of conditions 
from which ratings are deduced for other operating conditions. 

The term capacity is used in "Steam Heating" to denote the 
number of pounds of condensation per hour (Wi) which at uniform flow will 
pass through the specified apparatus when the pressure is maintained at 
1 lb. per sq. in. (Pi) above that of the atmosphere and the pressure at the 
outlet is that of the atmosphere (P2). 

Having obtained the capacity of any unit of steam-heating apparatus 
under these standard conditions, ratings may be estimated within a very 
small error, for other stated conditions of pressure difference, time or 
amount of heat content in the steam at given initial pressure. 

For any other pressure difference (P3 - P4) not differing greatly in 
amount from the standard pressure difference (Pi- P2), the quantity of 
discharge (W2) varies from the quantity (Wi) discharged under standard 
conditions in proportion to the square roots of the pressure differences; that 
is 



W, = W, 



P; 



iK 



or so nearly as to be within the normal errors of test. 

The distinction which should be made between capacity and rating, 
especially where rating is expressed in some indeterminate value like "square 
feet of radiation," can best be emphasized by examples. 

Assume a radiator trap, the capacity of which, with a drop from 1-lb. 
pressure above atmospheric in the radiator and trap, to atmospheric pressure 
in the trap outlet, has been found by tests to be 60 lb. of condensation per hr. 

Example 1. At what should this trap be rated in square feet of radia- 
tion on a coil in a room of 60-deg. average temperature, when the steam 
pressure in the coil is 4-lb. gauge and the vacuum at the trap outlet is 
10-in. or 5-lb. gauge .^* 

Answer: The pressure difference through the trap would then be 4 + 5, 
or 9 lb. The flow through the trap would be as the square root of 1 is to 
the square root of 9, or three times the capacity of the trap at standard 
1-Lb. pressure difference. This figures out 180 lb. per hr. 

Each pound of steam at 4-lb. gauge pressure gives up in condensing in 
a coil about 963 B.t.u. of latent heat, a total of 963 X 180 or 173340 B.t.u. 
per hr. Under the temperature due to 4-lb. gauge pressure the coil would 
probably give off 324 heat units per sq. ft. of surface. Therefore, the 
rating of this trap under the above conditions would be 324 divided into 
173340, or 535 sq. ft. of direct radiation. 

Example 2. At what would this same trap be rated in square feet of 

233 



radiation on the same kind of a coil similarly placed when supplied with steam 
at 3^-lb. gauge, and exhausting to atmospheric pressure at the outlet? 

Answer: The pressure difference tlirough trap being as stated, 3^ lb. 
per sq. in., the flow through trap will be as the square root of 1 is to the square 
root of i<4, or i^ the rate at 1-lb. difference in pressure, or 30 lb. of steam per 
hr. Each pound of this steam will give up in condensing about 969 B.t.u. 
of latent heat or 969 X 30 = 29070 B.t.u. per hour. 

Under the temperature due to 3^-lb. gauge pressure, the coil would 
probably give off 300 B.t.u. per sq. ft of surface. Therefore the rating of 
the trap under the conditions of this example would be 29070 divided by 300 
= 96.9 sq. ft. of direct radiation. 

In Example 1, the rating in sq. ft. of radiation is more than five times 
that in Example 2, the difference being due to the effect of differences in 
pressure on the same trap, which in both cases had the same capacity. 

Webster Modulation Supply Valves : Careful consideration should 
be given to the following facts concerning ratings of this type of apparatus: 

The capacity of a modulation valve should be based on the quantity 
of steam expressed in pounds per hour, or the equivalent B.t.u. of latent 
heat therein at 1-lb. pressure above atmospheric pressure which will flow 
through the valve when the outlet is at atmospheric pressure. 

This capacity may be referred to as the number of square feet of radiat- 
ing surface which will absorb the total latent heat of the steam flowing 
into the surface in a given time, at the commencement of which the tem- 
perature of the metal of the radiation and the room are at a stated degree 
below the normal room temperature. 

The steam requirements for all types of radiation are greatest during 
the heating-up period. This is the period during which the cold metal is 
absorbing heat, while at the same time the radiator as a whole is giving off 
heat by radiation and convection at approximately one half its normal rate. 
This statement is approximate because the temperature of the radiating 
surface is gradually increasing from the cold room temperature to the steam 
temperature, during this period. 

Other things being equal, it follows that the longer the allowable heating- 
up period, the greater is the proportion of capacity which may be expressed 
in the rating. Each type of radiation having a different weight of metal 
per square foot of heating surface and a different heat emission rate, will 
take a different rating of inlet valve of a given capacity. 

The consensus of opinion seems to be that the rating of a valve should 
be only such part of its capacity as will permit the heating of the entire 
radiator to steam temperature from a room temperature of 40 deg. fahr. 
in 20 minutes from the time the valve is fully opened, and this is taken 
as the heating-up period in the ratings given in the tables in this chapter. 
Radiation, according to type, varies in weight between 2.3 and 7 lb. per 
square foot of surface. 

This causes a marked difference in the steam requirements during the 
heating-up period, as well as a marked difference in the rating of any valve 
of given capacity. 

In Table 23-1 the warming-up requirements of the various types of 

234 



direct radiation in general use and, in Table 23-2, the normal heat emission 
in 70-deg. air, have been averaged under five classifications. From these 
averages, the factors in column 6 have been derived by which the capacity of 
any inlet valve in pounds of steam per hour at 1-lb. differential may be 
converted into rating in square feet of radiation of any of these general 
classes. 

Table 23-1. Basis for Rating Inlet Valves 

Heat required to raise temperature of metal from 40 to 210 deg. fahr. in 20 minutes. 
Temperature difference 170 deg. fahr. Specific heat, cast iron .12; mild steel .117 

Avg. wt. per sq. ft. cast-iron floor radiation 7.00 lb. x .12 x 170 =142.80 B.t.u. per sq. ft. 

" " " " cast-iron wall radiation 6.50 " x .12 x 170 =132.60 " " " " 

" " " " sheet-steel radiation 2.30 " x .117 x 170 = 45.75 " " " " 

" " " " IM-in- coil radiation 5.20 " x .117 x 170 =103.42 " " " " 

" " " " 1 -in. coil radiation 4.85 " x .117 x 170 = 96.47 " " " " 



Table 23-2. Rating Values for Modulation Valves 

For various types of direct heating surface 



Ccl. 1 


Col. 2 


Col. 3 


Col. 4 


Col. 5 


Col. 6 


B. t. u. per sq. 
ft. per hr. to 
maintain 210° 
in the rad. with 
room temp, of 
70° 


B. t. u. emitted 

in 1-3 hour 
during warming- 
up period = 1-6 
hourly rate 


B. t. u. per sq. 

ft. to raise 

temperature 

of metal 


B. t. u. per sq. 
ft. req'd in 20 
minute period. 

Total of 
Cols 2 and 3 


Combined 

hourly rate 

in B. t. u. 

C01.4X|? 


Factor for con- 
verting capacity 
into rating 
970 ^ Col. 5 


Cast-iron floor radiation 245 
Cast-iron wall radiation 296 
Sheet-steel radiation 260 
l}^-in. pipe coil radiation 326 
1-in. pipe coil radiation 296 


40.8 

49.33 

43.33 

54.33 

49.33 


142.8 
132.6 

45.75 
103.42 

96.47 


183.6 

181.93 

89.08 

157.75 

145.80 


551 
546 
267 
473 
437 


1.76\Avg. 
1.78/1.77 
3.63 
2.05 

2. 22 



To ascertain the rating in terms of square feet of radiation of any inlet 
valve for 20-min. heating-up period, multiply the capacity of the valve ex- 
pressed in pounds of steam per hour at that given pressure difference by the 
factor in column 6 corresponding to type of radiation and the result will be 
the square feet of that surface heated from 40 deg. to 210 deg. in 20 minutes. 

To ascertain ratings for any other period than 20 minutes, a new table 
must be prepared retaining columns 1 and 3. New column 2 will be deter- 
mined by multiplying the B.t.u. in column 1 by one-half the selected 
warming-up period in parts of one hour. (See seventh paragraph, page 234) . 

New column 4 will be the sum of new column 2 and standard column 3. 

New column 5 will be the product of new column 4 by (60 divided by 
the selected warming-up period in minutes). 

New column 6 will be the quotient of new column 5 into the latent 
heat in 1 lb. of steam at pressure. 

Having the rating for any particular valve for a particular class of 
radiation at 1-lb. differential, ratings at other pressure differences may be 
closely approximated by multiplying the 1-lb. rating by the square root of 
the other pressure difference. 

The normal average flow to a heated cast-iron radiator is about 250 
B.t.u. A properly designed modulation valve, when 0.6 open should supply 
the radiator with fV of the full-open flow, which is the approximate need 



235 



for full modulation effect. The balance, or iV of the openmg, is thus available 
for a quick warming-up period (20 minutes) when the valve is full open. 

Owing to the wide difference in area between standard pipe sizes, a 
valve of say 1-in. size must be used on all different sizes of radiators between 
its own maximum rating and that of the next smaller, or ^-in. valve. The 
wide-open 1-in. valve will therefore produce a much more rapid heating-up 
effect when connected to a radiator which is a little too large for a ^-in. 
valve, and the full modulation effect will be reached much before the valve 
is 0.6 open, which is the normal position for full modulation effect. This 
problem might be solved were it not for commercial considerations, by 
putting a restrictive valve piece in those valve bodies which are used on 
the lower half of the range. This would limit the flow at 0.6 open to 
about half way between the maximum for that particular valve and the 
maximum of the next smaller size. In this way, a valve having a total 
range of 45 to 78 sq. ft. of radiation at 0.6 open can be limited to 45 to 60 
sq. ft. of radiation, thus gaining the whole 0.6 range for controlling the 
degree of modvdating effect, instead of commencing to modulate only 
after about "^i closed and having but the remaining Js of the total move- 
ment for graduating the modulating effect. 

The ratings of each Webster Type W Modulation Valve for the stated 
conditions, at various positions of the pointer, are indicated in Figure 23-1, 
which in conjunction with Table 23-3 will assist in selection of a valve of 
the proper size for any set of conditions. 

Initial steam pressure alone is not a correct basis for valve rating or 
sizing. It is far safer to allow for maximum possible drop in line pressure 
when figuring the inlet pressure at the valve. Similarly, allowance must be 
made for variation in return line pressure, especially with vacuum systems. 



OPEN 
10- 
^- 

o 




/ 








^^^ 


"^ 






^ 


/ 


/ 


^ y 




^^ 






p^^-—-"'^ 






CO 

-a 

CO 

en 

1 r 


J 




















CH 

O) - 

g 


/// 


Y 


















03 
U 

= 9 


\lil 




















"en 

SHUT 


III 





















40 SO 120 160 200 240 

Square Feet of Average Cast-iron Radiation 



280 



320 



360 



400 



Fig. 23-1. 
the 



Rating of Webster Type W Modulation Valves. Based upon a differential of one pound at 
valve and fully heating the radiator in 20 minutes in a room temperature of 40 deg. fahr. 



236 



The condensation rate of radiation varies with the type of radiation or 
coil, its location, and the difference between outside and room temperatures, 
and allowance must be made accordingly. 

Table 23-3. Ratings of Webster Type W Modulation Supply Valves 

In square feet of average oast-iron direct radiation at various pressure dilTerences. Based on 20-niin. 
heating-up period from 40 deg. fahr. initial temperature* 









Pressure difference 






Size of valves 














1 oz. 1 


2 oz. 1 


4 oz. 6 oz. 


Soz. 


1 lb. 




Square feet of average cast-iron direct radiation 


y2" 


19 


27 


38 


47 


54 


76 


H" 


40 


57 


80 


98 


113 


160 


1" 


65 


94 


132 


63 


187 


265 


iH" 


112 


160 


225 


76 


319 


450 



Table 23-4. Ratings of Ordinary Angle-pattern Radiator Supply Valves 

In square feet of average cast-iron direct radiation at various pressure differences. Based on 20-min. 
heating-up period from 40 deg. fahr. initial temperature* 









Pressure difference 




Size of valve 












1 oz. ] 


2 oz. j 


4 oz. 6 oz. 8 oz. 


lib. 




Square feet of average cast-iron direct radiation 


'A" 


21 


30 


42 


52 


60 


84 


H" 


44 


62 


87 


107 


124 


175 


1" 


77 


102 


147 


180 


204 


294 


IM" 


126 


180 


2.52 


308 


360 


504 


iy2" 


187 


258 


364 


446 


516 


728 



Table 23-5. Ratings of Webster Double-service Valves 

In square feet of average cast-iron direct radiation at various pressure differences. Based on 20-niin. 
heating-up period from 40 deg. fahr. initial temperature * 



Size of valve 


Pressure difference 




1 oz. 


2oz. 


4 OZ. I 6 oz. 1 


8 oz. 


lib. 




Square feet of average cast-iron direct radiation 


H" 


42 


60 


85 


104 




120 


166 


1" 


69 


97 


138 


168 




195 


275 


IM" 


119 


168 


238 


292 




336 


475 


VA" 


172 


243 


343 


420 




486 


685 



* If the quick heading-up feature is disregarded and ratings are desired for normal requirements only, 
after the radiator has been heated up, multiply the values in the tables by 2.2. 

Webster Return Traps: Both the Webster Sylphon Return Trap 
and the Webster No. 7 Return Trap are rated on the basis of the quantity 
of condensation which they will pass under stated conditions. 

Owing to the fact that these traps when cold are fully open, the warm- 
ing-up period of a radiator has no bearing upon the problem of rating return 
traps even though the discharge of air and water are then at maximum. 

The thermostatically actuated members of Webster Sylphon and No. 
7 Return Traps are sensitive to very slight changes of the temperature of 

237 



the surrounding medium. The motion of the members is due to the difference 
in pressure and temperature on a hermetically sealed charge, partially 
liquid, partially gas and vapor, which responds to changes in temperature 
with material changes in volume and pressure, and this provides a power- 
ful force to actuate the valve piece. 



Table 23-6. 



Ratings of Webster Return Traps in Pounds of Condensation and 
B.t.u. per Hour at Various Pressure Differences 



Size and type 


Pressure difference 


of trap 


2 oz. 


4 


oz. 


6 oz. 


8 oz. 


lib. 




Lb. 


B. t. u. 


Lb. 


B. t. u. 


Lb. 


B. t. u. 


Lb. 


B. t. u. 


Lb. 


B. t. u. 


K"-512 & 712 

}^"-522 & 722 

Ji"-533 & 733 

l"-544 & 744 

lM"-545 & 745 


14 

22 

66 

133 

265 


13580 

21340 

64020 

129010 

257050 


19 

31 

94 

188 

,375 


18430 

30070 

91180 

182360 

363750 


23 

38 

115 

230 

459 


22310 

36860 

111550 

223100 

445230 


27 

44 

132 

265 

530 


26190 

42680 

128040 

257050 

514100 


38 

62 

187 

375 
750 


36860 

60140 

182390 

363750 

727500 



Table 23-7. Initial Steam Pressures and Pressure Drops through Supply Pipes, 

Modulation Valves and Return Traps of the Heating Systems of 

Different Tjrpes of Buildings 



Case 


Approximate steam 
pressure in 
zero weather 


Pressure drop 

through supply 

piping 


Average pressure differential 
through valves 




Modulation 
supply valve 


Return trap 


A 


}4to%\b. 


yg lb. with mini- 
mum run-400 ft. 


2oz. 


2oz. 


B 


ItolJ^U). 


i<4 lb. with mini- 
mum run-400 ft. 


1 oz. 


4 to 6 oz. 


c 


1 to 2 lb. 


A lb. with mini- 
mum run-400 ft. 


4 oz. 


4 to 6 oz. 


D 


Vi to 2 lb. 


J^ to 1 lb. 


4 oz. 


4 to 6 oz. 


E 


VA to 2 lb. 


1 lb. 


4 to 6 oz. 


8 to 12 oz. 



NOTE: In modulation systems in conjunction with low-pressure boilers of limited water capacity, it is essential that the 
drop in pressure through the system be kept well below the pressure due to the static head between the modulation vent trap 
and the water line of the boiler. Special apparatus may be provided to return water to boiler where, owing to structural con- 
ditions, the above outlined conditions cannot be obtained 

Note: Webster Water-seal Traps in the few cases where they are used 
are rated same as the Sylphon and No. 7 Traps. 

Selection of Modulation Supply Valves and Return Traps: 
For any given installation the choice of the proper sizes of modulation 
valves and return traps will depend upon the available pressure differential 
through the valves. 

This, in turn, is dependent upon the steam pressure maintained at 
the boiler and the drop in pressure through the piping system. Wlaile it 
is not possible to lay down hard and fast rules which are applicable for every 
installation, the following cases are given as representative types of systems 
in general use. Cases A to D inclusive, given in table 23-7, relate to 

238 



modulation systems, with open returns terminating at the boiler in a 
modulation vent trap or some similar forms of apparatus. Case E is the 
usual type of vacuum system. The proper sizing of supply and return pipes is 
explained in detail in Chapter 1 1 and the pressure drops referred to below are 
found in Table 11-8. 

Case A: Residences and small apartments where the firing is inter- 
mittent, frequently extending over eight or perhaps ten-hour periods and 
where it is necessary to operate at low steam pressure. In mild weather it 
may be possible to circulate steam through the entire system at or perhaps 
slightly below atmospheric pressure. In zero weather a pressure will be 
maintained at the boiler of from 3^ lb. to ^ lb. depending upon the kind 
of fuel, length of firing period and condition of fire. 

Case B: Very large residences, apartment houses, small ofiices and 
public buildings where large size cast-iron sectional or steel boilers are 
installed, operating at low steam pressure and under the care of a regular 
attendant, with continuous firing instead of intermittent. 

Case C: Schools and similar buildings containing large amounts of 
indirect radiation where there are periods of interruption in maintaining 
pressure on the system and where quick circulation is desired when starting. 

Case D: Buildings where the pressure is maintained constant by means 
of a reducing valve and steam is taken at higher pressure either from its 
own boiler plant or from a street system. 

Case E: Ofiice buildings, industrial plants, etc. in which a vacuum 
system is installed using live steam at reduced pressure, or exhaust steam 
from engines, pumps and auxiliary apparatus, supplemented by live steam 
passed through a reducing valve. The steam pressure at the entrance to 
the supply piping in zero weather will range from IJ^ to 2 lb. and the vacuum 
on the far end of the return line will be approximately 2-in. 

Webster Heavy-duty Return Traps: This trap is for use where 
large quantities of condensation are to be handled at any temperature. 
It has a cone-shaped float-operated valve piece seating on a sharp-edged 
orifice, the seat being below the low-water line of the trap. The air entering 
the trap is allowed to pass to the return line, through a connection controlled 
by a thermostatically operated trap discharging through a cored passage to 
the return line. In special cases the opening through the air orifice may be 
adjusted by hand. 

Table 23-8. Ratings of Webster Heavy-duty Traps in Pounds per Hour at 
Various Pressure Differences Through the Valve 

No allowance made for pressure drop in the connecting piping between 
radiation and trap or from trap through run-out to return 



Size 


Pressure difference 


of trap 


MLb. 


ILb. 


2 Lb. 3 Lb. 


4 Lb. 


5 Lb. 


10 Lb. 


15 Lb. 


0019 
019 
119 
219 


700 
1250 
2100 
5600 


1000 
1800 
3000 
8000 


1400 1700 

2500 3050 

4200 5100 

11200 13600 


2000 

3600 

6000 

16000 


2200 

4000 

6700 

17900 


3150 

5700 

9500 

25300 


3900 

7000 

11700 

31100 



Webster Series 20 Modulation Vent Traps: Capacities of Series 
20 Modulation Vent Traps are based upon the assumption of an air flow of 

239 



6000 cu. ft. per hour through a vent orifice of 1 sq. in. area from a pressure 
of 1 lb. above atmosphere to atmospheric pressure. This quantity is 
obtained as follows: . 

Velocity of flow in feet per second is V = C ^ 2 gh, and the quantity 
in cubic feet per Jiotir is Q = 3600 x av. in which Q is the quantity in cubic 
feet, c is a constant (0.7), h is the height of a column of air in feet, required 
to produce a pressure of 1 lb. per sq. in., a is the area of the orifice in 
square feet, v is the velocity in feet per second and g is 32.17. 

1 Lb. of air contains approximately 13.2 cu. ft. For any other pressure 
difference not varying greatly in amount from the above standard pressure 
difference, the quantity of discharge will be substantially proportional to 
the square roots of the pressure difference. Assuming that 50 sq. ft. of 
cast-iron radiation, with connecting supply pipes, will contain 1 cu. ft. of 
space, from which the air must be discharged before steam will enter, the 
following basic data applies for Modulation Vent Traps. 

Table 23-9. Basic Data for Modulation Vent Traps 



Size of trap 


0020 


020 


120 


220 


320 


Cubic feet of air discharged per 
hour at 1 lb. differential 


85 


660 


1176 


2652 


4710 


Cubic feet of air discharged per 
hour at 1 oz, differential 


21 


165 


294 


663 


1178 


Square feet of direct radiation 
per hour at 1 oz. differential 


1050 


8250 


14700 


33150 


58900 



Referring to page 117, it is to be noted that air vent traps are rated 
on the basis of flow of initial air from a system in 40 min. with 1-oz. 
differential pressure through the system. The table below gives the ratings 
on this basis for which the Webster Modulation Vent Traps should be 
applied. 

Table 23-10. Ratings of Series 20 Modulation Vent Traps 



Size of trap 


0020 


020 


120 


220 


320 


Square feet of direct radiation 
in 40 min. at 1 oz. pressure 


700 


5500 


9800 


22100 


39265 


No. of *-in. unit vent 
valves required 


1 


1 


2 


3 


5 



Modulation Vent Valves are required wherever it is desired at times 
to operate the heating system at a pressure less than atmospheric. Where 
large heating units are under automatic temperature control, the use of 
these vent valves is inadvisable unless vacuum breakers are provided at the 
proper points in the piping system. 



240 



CHAPTER XXIV 

Appliances for Webster Systems of 
Steam Heating 

WEBSTER Appliances used as parts of heating systems are illus- 
strated and briefly described in the following pages. 
These appliances include: 

Return Traps Gauges 

Heavy-duty Traps Modulation Vent Traps 

High-differential Heavy-duty Traps Modulation Vent Valves 

Modulation Supply Valves Damper Regulators 

Double-service Valves Hyio Vacuum Controllers 

Oil Separators Hylo Traps 

Grease and Oil Traps Conserving Valves 

Suction Strainers Boiler Feeders 

Dirt Strainers High-pressure Traps 

Vacuum-pump Governors Hydro-pneumatic Tanks 

Lift Fittings Expansion Joints 

Return Tanks Steam Separators 

Water Accumulators Feed-water Heaters 
Vapor Economizers 

Return Traps for Automatically Removing Water of 
Condensation and Air from Heating Units 
The return trap, to be perfect in operation, should — 
(a) Allow the condensation to escape at a temperature slightly below 
that of the steam. 

(6) Drain the radiator thoroughly by gravity, without the assistance 
of pressm-e or vacuum. A water-logged radiator loses efficiency because 
part of the heating is being done by the water condensed from steam, which 
is at lower temperature, and because a water-logged radiator is also an air- 
bound radiator. 

(c) Permit continuous removal of air. An air-bound radiator loses 
efficiency because the steam cannot completely fill it. 

(d) AutomaticaUy close to prevent loss or waste of steam. 

(e) Work within the widest necessary range of pressure and vacuum 
variation. , 

(/) Require no adjustment under such variations. 
(g) Be noiseless in operation, if used where noise is objectionable. 
(h) Be so designed that the valve will close even where dirt may be 
present in normal quantities. 

(0 Be durable and require little or no attention or repairs. 

241 



The efficiency of the radiator will depend upon how nearly the return 
trap meets these requirements. 

A return trap working sluggishly will not only hold back the water, 
but will "bottle up" the air and air-bind the radiator, thus defeating the 
very purpose of a vacuum system. 

As different methods must at times be employed in connection with 
direct radiators, blast sections, riser drips, main drips, dripping hot-water 
generators, factory coils, etc., Webster Return Traps are made in several 
forms, at least one of which will meet the requirements of any installation. 

100% RADIATOR EFFICIENCY 



1 




SUCCESSFUL 
OPERATION 
AT VARYING 
PRESSURES 


1 




1 


«« 





AUTOMATIC REMOVAL 
OF AIR AND WATER 
OF CONDENSATION 
WITH NO LEAK- 
OF STEAM 



99.5 PLUS PER CENT 
VAPOR EFFICIENCY 



NO INTERFERENCE BY DIRT WITH THE PROPER FUNC- 
TIONING OF TRAP 

Fig. 24-1. The requirements of a perfect radiator trap 

The type and capacity of the trap required depend upon the point of 
application, the amount of air and water to be removed, the character of 
the heating surface and the pressure and vacuum carried. It is important 
that all of these conditions shall be studied carefully before selection is made 
of the size and type of trap for specific applications. 

The Webster Sylphon Trap 

The Webster Sylphon Trap has been specially designed to meet the 
requirements for a perfect radiator trap. It maintains the highest possible 
efficiency within the heating surface by the removal of all of the products of 
condensation, and as this is effected without loss of steam, it is economical 
in the highest degree. The economy is especially apparent when reduced- 
pressure live steam is used in whole or in part, or where, before its appli- 
cation it has been necessary to waste large quantities of cold water to cool 
the heating system returns before they enter the vacuum pump. 

The operating member consists of a Sylphon bellows, which carries a 

242 



conical-shaped valve piece, closing against a sharp-edged seat. The bellows 
member is very sensitive, operating to close or open the valve port by the 
slightest change in the temperature of the sm-rounding medium, and is the 
most durable form of thermostatic device so far known. The multiple 
construction of the seamless brass folds forming the bellows distributes the 





Fig. 24-2. No. 512 Model H Webster Sylphon Trap. Size of pipe connections, ^-in. 





Fig. 24-3. No. 522 Model H Webster Sylphon Trap. Size of pipe connections, i^-in. Nos. 512 and 522 

differ in rating and lift of valve. No. 522 being larger 
No. 523 has same size body mechanism and rating as No. 522, but has J^-in. pipe connections to meet 

unusual specifications in that respect 



strain of movement and increases the hfe of the operating member. In- 
crease in steam pressure on the outside of the bellows is compensated by the 
increase in pressure on the inside of the bellows. 

The sensitiveness of this member is due to the flexibility of the walls 



243 



of the bellows to movement in the desired direction and the small amount 
of movement of each fold when acted upon by the pressure surrounding and 
also that generated within the bellows. The sum of the small movement 
of each of the many folds gives a greater total lift of the valve than any other 
device for similar purpose. 

The conical valve piece and sharp-edged seat give increased capacity 





Fig. 24-4. No. 533 Model H Webster Sylphon Trap. Size of pipe connections, 54-in. 

No. 534 has same size body with 1-in. pipe connections to meet unusual specifications 
No. 544 is similar, but larger throughout for 1-in. pipe connections and greater duty 
No. 545 is the largest in proportions and ratings. For l}i-in. pipe connections 

for discharge of water, and the valve does not become inoperative due to 
presence of dirt and scale. 

The Webster Sylphon Trap will close quickly and positively when steam 
reaches the bellows, while the water and air will be freely withdrawn or dis- 
charged at temperature slightly below that of steam at existing pressure. 

This means that every radiator in use will be thoroughly efficient in 
heating, as there will be no "pocketing" of air or "bottling up" of water 
within the radiator. 

As the valve is full open when cold, the radiator will be fully drained 
when steam is turned off, and the vacuum condition existing in the return 
line will extend within the radiator, assisting circulation when steam is 
again turned on. 

Operation : As the steam first flows into the cool radiator, it expels the 
contained air and initial condensation through the wide-open trap. As the 
radiator warms up from inflow of steam, the bellows commences to expand, 
but remains partiaUy open as long as the air and water in the trap are at a 
lower temperature than that of the steam. The moment the air is entirely 
expelled from trap body, and replaced with steam, the valve closes. It 
opens again when water and air at a temperature slightly less than that of 
the steam accumulate in the trap. Then, as the water and air escape and 
are replaced in the trap body by steam, the trap again closes, thus complet- 
ing its cycle. 

244 



Table 24-1. Models and Dimensions of No. 5 Sylphon Traps for Working 
Pressure Up to 10 Lb. per Sq. In. 

For convenience in making pipe connections, Webster Series 5 Sylphon Traps of the smaller sizes Eire made 
with four types of bodies as shown. Model H or angle is the one most used 




Model H 
Angle 




Model G 
Straightway offset 




Model R 
Right corner 




Model L 
Left corner 



Fig. 2 1-3. Bodies of Webster Series 5 Sylphon Traps 



■^-C-^ A 




Size 


Trap no. 
& model 


A 


B 


c 


D 


J^" 


512H 


3" 


1^" 


IKs" 


41/9" 


Vs" 


522H 


35^" 


W^' 


ll%" 


5M" 


%•• 


523H 


W^' 


2" 


lA" 


5M" 


M" 


533H 


4i^" 


2Vs" 


IM" 


^%" 


1" 


534H 


4J/8" 


2^" 


Wi" 


5H" 


1" 


544H 


4^" 


2^" 


2" 


6M" 


IM" 


.545H 


xy^- 


2,%" 


2" 


6H" 



Fig 24-6 





Fig. 24-7 



Fig. 24-8 



Size 


Trap no. and model 


A 


B 


c 


D 


E 


H" 


612G, 512R or 512L 


3" 


IK2" 


1" 


iVi" 


IH" 


H" 


522G, 522R or 622L 


3-i-s" 


^Vi" 


IK" 


5=4" 


15^" 


%" 


523G, 523R or 523L 


3K" 


nv 


IK" 


5A" 


IK" 


M" 


533G 


iA" 


2,V" 


iM" 


5%" 


Not 


1" 


534G 


4H" 


2 A" 


m" 


0" 


made 



For ratings, see Table 23-6, page 238. 
245 



The Webster No. 7 Trap 




Fig. 24-9 Exterior and interior of No. 722 Webster Trap 

Webster No. 7 Traps also realize all of the requirements for thoroughly 
satisfactory operation as radiator traps. They are applied at the outlets 
of steam radiators and coils, at drip points 
on steam supply hues and risers and at the 
outlets of blast sections on fan coils and 
provide continuous free and thorough re- 
moval of entrained air and water of con- 
densation, without permitting any live steam 
to escape to waste in the return lines. 

The inlet of the trap is attached to the 
radiator, coil or supply line by means of the 
union connection, and the outlet is piped 
into the return line. 

The thermostatic member is inboard of 
the valve seat where not affected by pressure 
or temperature in the return line. 

The diaphragm, which forms the active 
part of the operating member, is built of 

Table 24-2. Models and Dimensions of Webster 

Series 7 Traps for Working Pressure 

Up to 10 Lb. per Sq. In. 

For convenience in making pipe connections, Webster Series 
7 Traps are made with four types of bodies as shown. Model 
H or angle is the one most used 



Size 


Trap 
no. 


A 


B 


c 


D 


E 


y^' 


71 2H 


Wi" 


ll^" 


1^" 


015// 

-16 




Vi" 


722H 


W2" 


lA" 


IJ^" 


•■5,^" 




%" 


723H 


SVs" 


It^" 


VA" 


3i%" 




%" 


733H 


4M" 


l%" 


2H" 


4A" 




1" 


744H 


4M" 


2" 


2K" 


4i%" 




\%" 


745H 
712G 


iH" 


2" 


2y2" 


4i%" 




M" 


712R 
712L 
722G 


3M" 


2,^" 


M" 


3^" 


2H" 


¥2" 


722RI 
722L 


33^" 


2M" 


M" 


^'A" 


2M" 



For ratings see Table 23-6, page 238 




Fig. 24-11 



246 



four successive phosphor-bronze plates instead of the usual two and for that 
reason there is greater diaphragm movement and the valve has greater lift 
than usually found in traps of similar types. 

The expansion and contraction of the diaphragm member is produced 
by differences in volume and pressure of a hermetically-sealed fluid charge 
in response to changes in temperature. Even a very slight temperature 
change produces a powerful force to actuate the conical valve piece, which 
in closing, fits tightly on a sharp-edged seat. 

No part of the valve mechanism is impaired by the quantities of the 
scale and dirt which normally exist in steam-heating systems. 



Webster Heavy-duty Traps 




Fig. 24-12. Series 19T Webster Hea-vry-duty Trap 
with thermostatically controlled air bypass 

Series 19T with Thermostati- 
cally CONTROLLED AlR ByPASS. FoR 

15 -LB. Maximum Operating Pressure : 
The Webster Heavy-duty Trap handles 
unusually large quantities of conden- 
sation, and is for dripping main supply 
risers or mains entering or leaving the 
building, for draining large sections 
of blower coils or pipe manifolds, for draining hot-water generators, etc. 

Insofar as the discharge of condensation is concerned, this trap operates 
on the float principle and has a large water outlet to withdraw the con- 
densation as quickly as possible from the unit to be drained. 

Air is eliminated by means of a thermostatically actuated by-pass, as 
shown in Figure 24-12. The operating device, the valve piece and seat are 
the same as used in the Webster No. 7 Trap. 

247 




The body and cover are of cast iron. The cover is bolted on, easily 
removable and so designed that all interior parts are exposed for inspection 
upon its removal. The outlet is in the bottom of the body, and the inlet 
may be on either end, with the opposite opening plugged. It is recom- 
mended that wherever practical the inlet farthest away from the valve be 
used. An opening is provided at the bottom of the float chamber as a clean- 
out by-pass and for draining the trap when out of use. 

The float has ample leverage to avoid sticking of the valve. The cone- 
pointed valve and square-edged seat prevent accumulation of dirt where it 
might clog the port. The valve is water-sealed at all times, as the water 
level is always well above the seat. The float lever is kept within the ver- 
tical plane of action by guide flanges cast into the trap body. 

This trap can also be furnished special with hand-controlled air and 
by -pass, where unusual conditions require such construction. In such cases 
the air port is adjustable for any desired degree of constant leakage. 

Some of the many practical applications of the Series 19T Trap will be 
found in Chapter 22. Ratings are given on page 239 and dimensions on 
page 249. 





Fig. 24-13. Conventional arrangement of Series 
20 Webster High-differential Heavy-duty Trap 
and Special Webster Dirt Strainer (Inlet pipe 
may be connected to opposite end if desired) 




Fig. 2 1-14. Series 20 Webster High-ditferential 
Heavy-duty Trap for working pressures up_to 
50 lb. per sq. in. 



248 



High-Differential Type, Series 20, For Working Pressures up 
TO 50 LB. per sq. in.: The Webster High-differential Heavy-duty Trap 
is recommended for steam pressures higher than 15 lb. and where 
large quantities of condensation may be discharged. It is particularly 
applicable to problems like or similar to those described in Chapter 19. 

The trap body is constructed of cast iron and has an easily removable 
cover of the same material. The valve is of the balanced type and operates 
against a steam-brass seat. The ball float is extra heavy to withstand the 
higher pressures. 

The Webster High-differential Heavy-duty Trap may be operated 
with a constant leakage through a hand-adjusted air vent, though the best 
practice calls for control of the air discharge by means of a thermostatically 
actuated valve in a by -pass of pipe and fittings as shown in Figure 24-16. 
It is important to note in this case of higher than ordinary steam pressure, 
that the thermostatic trap must be of the No. 8 Sylphon type. (See page 275.) 

Table 24-3. Dimensions of Webster Heavy-duty Traps 

All dimensions in inches and subject to slight variation 




Drain Opening 
Fig. 24-15. Standard type— Series 19T 




A=Size Outieti.^ 



^i Plugged 



Drain Openino 
Fig. 24-16. High-differential type — Series 20 



For ratings of Heavy-duty Traps see Table 23-8, page 239 
Series 19T, with thermostatically controlled by-pass 



Number 


A 


Ai 


B 


c 


D 


E 


F 


G 


H 


V 


V 


w 


0019-T 


H 


H 


13M 


1 


■J'A 


12^ 


iVs 


3Vk 


2H 


9H 


-^Vh 


y?. 


019-T 


% 


H 


15M 


1 


8 


15 


4H 


SVs 


m 


9H 


6J4 


■H 


119-T 


IVa. 


iH 


193/8 


IH 


9 


18^ 


5^/8 


VA 


4^ 


ny2 


7 


1 


219-T 


2 


2 


20ys 


1^8 


10^ 


19 J^ 


6% 


m 


m 


13 M 


8 


1K2 



Series 20, high-differential type 



, Number 


A 


Ai 


B 


c 


D 


E 


F 


G 


H 


n 


V 


W 


020 
120 
220 


H 
IM 
2 


IM 
2 


15^ 

i9ys 

20^ 


1 


8 
9 

WA 


15 

183/^ 

19}^ 


6ys 




2% 


12M 
133^ 


6M 

7 

8 


1 

1^ 



249 



The Webster Type W Modulation Valve 








Fig. :2 1-17. The Webster Type W Modulation Valve — shown in partly open position 

The Webster Type W Modulation Valve is a special-purpose radiator 
valve of the quick-opening, non-rising stem, straight-lift type, built for com- 
plete opening or closing with less than a single turn of the handle. Its 
manipulation is as simple and its control as effective as the movement that 
regulates light from a gas jet. 

As the names implies, the principal function of the Webster Modulation 
Valve is to facilitate "modulation" of temperature in each room according 
to the desires of the occupant, by varying the amount of steam admitted 
to the radiator or coil. A pointer attached to the handle traveling over a 
graduated dial indicates the amount of valve opening at all times. 

With the valve full open, the discharge capacity through the ports is 
nearly equal to that of the outlet connection of the valve. 

Less than three-fourths of the valve lift and opening movement is re- 
quired to produce modulation up to normal full heating requirement. The 
rest is in reserve to admit more steam during the heating-up period, as needed 
to compensate for the higher condensation rate caused by contact with the 
cold radiator and its surrounding air. 

Construction Details : The modulation effect is produced by a pat- 
ented modulating plug which varies admission of steam in progressive vol- 
ume with the lift of the valve piece. 

A Jenkins disc is used to insure tight closing. With the exception of 
this and the handle, all parts are of brass. The handle is of special composi- 
tion and so formed that the hand of the operator does not come into contact 
with the heated surface of the valve body. 

Application: The Webster Modulation Valve may be used on either 
hot-water type radiators (having connections from section to section at both 
top and bottom) or with steam type radiators (bottom connections only), 
although the former type is preferable from the standpoint of convenience. 

Where the Webster Modulation Valve is used with the hot-water type 
of radiator, it should be placed at the top to bring the operating handle in 

250 



the most convenient location and to permit the steam to circulate across 
and downward. Air and condensation, being heavier, fall to the bottom 
in advance of steam and give full efficiency to the heated part of the radiator. 

Where the Webster Modulation 
Valve is used with a steam type radiator, 
it is possible by the use of an inlet section 
of the hot-water type to secure the con- 
venience of operation which is obtained 
where the valve is placed at the top of 
the radiator. 

If placed at the bottom of radiators, 
because other connections cannot be 
arranged, the inlet bushing should be 
eccentric and so located that the center 
line of the radiator or inlet is above that 
of the radiator outlet. This is essential 



Fig. 24-18. Typical application of the exten- 
sion stem principle 




to prevent condensation from drain- 
'^^gT Jj ing by gravity through the supply 
^'^^ instead of the return connections, 

thus eliminating water-hammer. 




Fig. 24-19. Typical appli- 
cation of chEiin attach- 
ment to Webster Type W 
Modulation Valve 



mi 



Extension Stem: For attachment to radiators concealed in recesses or 
under window seats behind grilles, the Webster Modulation Valve is provided 
with an extension stem and a special dial that may be placed on the face, top 
or end of the grille or seat (see Figure 24-18). 

The stem has a universal joint on each end, which permits operation 
of the valve from a point not directly in line with the valve stem, and at 
the same time provides enough play to avoid sticking or binding from mis- 
alignment or shifting caused by expansion and contraction. This con- 
struction also avoids the necessity for very accurate stem connections. 

The outside indicator dial, pointer and handle are similar to those used 
on top of the standard valve. 

Chain Attachment: The Webster Modulation Valve to be applied to 
radiators or coils located in skylights, overhead, or on walls near the ceiling, 
can be fitted with a chain attachment for convenience in obtaining every 
advantage of the modulation feature (Figures 24-19 and 24-20). 

The chain wheel is substituted for the handle of the standgu-d type of 
Modulation Valve and the chain is made just long enough to permit easy 
grasp from the floor. Tags are attached to bottom of the chain in such 
positions that the hanging end indicates the degree of valve opening. 

Table 24-4. Diniensions of Type W 
Modulation Valve 




Size 


A 


B 


C 


D 


M 


■ 2H 


IK 


2Js 


4H 


K 


Wi 


Wi 


2ys 


4^ 


1 


3M 


IH 


2H 


53/8 


IM 


3 Si 


o 


2H 


6 



All dimensions in inches and subject to slight variation, 
o I <>i ^°^ ratings, see Table 23-3, page 237 

The Webster Double-service Valve 

This is one of the latest developments of apparatus for simplifying 
piping connections in steam heating systems in certain types of construction. 

Common practice in buildings of only one story and in some other 
instances calls for a steam supply line along the ceiling of the first floor to 
feed each radiator or coil through a short down-feed riser, which must be 
dripped into the return line. This multiplicity of unsightly connections is 
simplified by the use of Webster Double-service Valves, applied in the 
manner shown in Figure 24-23. 

This valve performs "double service, " as a supply valve for the radiator 
and as a trap for draining the riser. 

The thermostatically controlled valve is open when there is water or air 
in the riser, and permits the condensate to flow through a bypass in valve 
body into the radiator and thence into the return. Upon presence of steam 
the thermostatic member expands, closes the valve, and thus prevents 
waste of steam. 

252 




Fig. 24-22. The Webster Double-service Valve 



£ 



^Supply Main 



1 



7=^ 



fe 



Supply Riser- 



All Connections to be 
Irom Bottom of Main 



Steam is admitted to the radia- 
tor in amount desired, by means of 
the quick-opening valve, which is pro- 
vided with a graduated dial and handle. 
This valve does not include the modula- 
tion feature, as the supply valve is designed only for 
quick opening without respect to modulating effect. 

The valve body is best-quality cast iron, and all 
other parts except the valve disc and handle are brass. 
Nut and nipple are provided only at one end to promote 
easy installation. AH outside parts are nickel-plated. 



WEBSTEB 

DOUBLE SERVICE 

VALVE 





Eccentric Bushing 
7 WEBSTER 

RETURN TRAP 



H 



Fig. 24-23. Application of a Webster Double-service Valve to a standard cast-iron radiator 

253 



The thermostatic member, which is built up of four discs of phosphor 
bronze and filled with a volatile fluid, the conical valve piece and the sharp- 
edged seat are of standard pat- 
tern as used in the Webster No. 7 
Trap. 

The inlet valve is provided 
with a ring seat and Jenkins disc 
to insure tight closing. Its quick- 
opening feature is provided by a 
screw stem of such pitch that the 
valve will be completely opened 
with less than a complete tm-n of 

Fig. 24-24. The Webster Double-service Valve 

Table 24-5. Dimensions of Webster Double-service Valves 




Size 


A 


B 


c 


D 


E 


F 


G 


H 


J 


M 


3M 


1 


2J^ 


m 


Wa 


2M 


2% 


9M 


Vs 


1 


m 


IM 


Wi 


5^ 


I'A 


3 


3 


9H 


% 


IM 


4 


iy2 


2% 


6M 


IM 


3^ 


SVs 


lO^A 


Vs 


m 


4K 


Wi 


2% 


8 


IM 


3^8 


SVs 


iiM 


% 



All dimensions in inches and subject to slight variation. For ratings, see page 237 

Webster Oil Separators 

The Series 21 Webster Oil Separator is made in two patterns — for either 
horizontal or vertical direction of steam flow. The baffles in the horizontal 
type are double-hooks so that either nozzle may be used as the steam inlet. 
The vertical pattern is suitable for up-flow of steam only. 

An outstanding feature of tliis series of Webster Oil Separators is the 
position of the manhole cover which makes it possible to inspect or clean 
the device without disturbing the piping. 

Septuation of oil and condensation is effected by impact upon and 
adhesion to baffles and by abrupt changes of direction of flow through the 
separator. 





Fig. 24-25. Series 21 Webster Oil Septirator Standard Horizontal Type 

254 





Fig. 24-26. Series 21 Webster Oil Separator, Standard Vertical Type, lor upflow only 

There is no unobstructed path through any Webster Oil Separator, 
yet the free area through which steam must pass is several times greater 
than inlet and outlet area, thus minimizing pressure loss due to friction. 

The use of these separators pro- 
tects boiler heating surfaces and inte- 
rior surfaces of heating systems from '" "" ""° '^^"'^ """ 
the oil deposits that otherwise seriously K~] 



Exhaust 

/Main 



WEBSTER OIL SEPARATOR 

I 



To Heating Supply Main/ 

Size of Vent to correspond with Size 
of Tappino in Top ot Grease Trap 
WEBSTER GREASE AND OIL TRAP 




Exhaust 
MaiRv 




ize ol Vent to correspond with Size 
f Tapping in Top of Grease Trap — 



Hot Well 



By Pass ' 
-Laroerthan Drip of Oil Separator 



t,.y — 




^ 



Free Vent 



floor Line 




This Distance Irom Bottom 
of Oil Separator to the 
Inlet ot Grease Trap must 
be at least Five Feet '5'-0'') 



Gate Valve 



Floor Line 



Fig. 24-27. Method of connecting a Webster Grease 

Trap to a Webster Oil Separator, where a partial 

vacuum may at times be carried on the 

heating main 



Fig. 24-28. Typical method of draining Webster 
Oil Separator through a Webster Grease 
Trap, where positive pressure is main- 
tained at all times 



impair heat transmission and often cause serious damage. 

These separators may also be used for such special purposes as removing 
moisture or oil from compressed air and other gases. 

That Webster Separators are eflBcient in all their standard and special 
forms is indicated by absolute satisfaction in over 15,000 installations. 



255 



The material ordinarily used in the 
shells is close-grained cast iron, but spe- 
c al shell of semi-steel, cast steel or other 
material can be furnished at extra cost. 

Table 24-6. Maximum Ratings of Oil Sepa- 
rators in Lb. per Min. at Average Gauge Pres- 
sures Based on 6000 Ft. per Min. Pipe Velocity 



Oullel 





Pressu 


re, lb. per sq 


in. 




Size 





5 


10 


IS 


2 


5.2 


6.7 


8.4 


10. 


3 


11.4 


15. 


18.6 


22. 


4 


19.8 


26. 


32. 


38. 


5 


31. 


40.6 


50.2 


59.7 


6 


45. 


59. 


73. 


86.5 


8 


78. 


102. 


126. 


150. 


10 


123. 


160. 


200. 


235. 


12 


176. 


231. 


285. 


339. 


14 


222. 


292. 


361. 


427. 


16 


294. 


385. 


475. 


565. 


18 


375. 


492. 


608. 


720. 


20 


452. 


595. 


735. 


870. 


22 


550. 


725. 


900. 


1060. 


24 


660. 


870. 


1070. 


1270. 




For lower velocities, the pounds carried will be propor- 
tional as the lower velocity is to 6000 p- 24-'i0 

Table 24-7. Dimensions of Webster Oil Separators 

All dimensions in inches. Companion flanges furnished only on special order; drilled 
low-pressure standard unless otherwise ordered 
Standard Horizontal Type (Fig. 24-30) — for steam flow in either direction 







Dimensions 










Flanges 




SIZE 


B 


D 


E 


F 


G 


Drip 


Outside 
diameter 


Bolt 
circle 


No. & sizes 
of bolts 


*iy2 


10 


6ys 


33^ 


iVs 


(yVs 


M 








*9 


lOM 


8 


m 


5J/8 


7M 


M 








9 


12 


8 


4,3,-8 


51/8 


7J4 


M 


6 


4M 


l-Vs 


2^ 


13 M 


lOM 


5^ 


6 


8Vs 


H 


7 


5}^ 


-i-H 


3 


15 


11^ 


6J^ 


63^ 


93^ 


% 


7M 


6 


4r-H 


^Vz 


15^ 


103^8 


5 


(>h 


lOK 


1 


8K 


7 


4^ys 


4 


161^ 


IIM 


5}4 


6H 


1134 


1 


9 


7J^ 


8-% 


5 


iiH 


115^ 


5h 


7 J/2 


13M 


1 


10 


834 


8-H 


6 


19 


12}^ 


6 


8M 


13^ 


1 


11 


934 


8-M 


8 


21 


12K 


(>H 


8^8 


18^ 


IM 


IW2 


iiM 


8-M 


10 


99 


16 


8J^ 


9^8 


19M 


13^ 


16 


1434 


12-H 


12 


24H 


18^ 


9ys 


WA 


22 J^ 


2 


19 


17 


12-ys 


14 


28 


99 


IVA 


n]i 


22 J^ 


9 


21 


18 M 


12- 1 


16 


31 


25 M 


13 H 


13 


233^ 


2V2 


233^ 


2134 


16- 1 



*Screw connections only. Standard Vertical Type (Fig. 24-29)— for up-flow only 







Dimensions 








Flanges 




SIZE 


B 


D 


E 


H 


Drip 


Outside 
diameter 

ly 


Bolt 
circle 


No. & sizes 
of bolts 


3 


1334 


7^ 


334 


7M 


H 


6 


4-^8 


3M 


uys 


m 


4 


9 


H 


834 


i 


4-5^ 


4 


16 


9^8 


4.34 


103^ 


1 


9 


-y-i 


8-54 


5 


16^' 


12 


534 


1234 


1 


10 


834 


8-M 


6 


18 


15M 


6^8 


15M 


1 


11 


9H 


8-M 


8 


2034 


1734 


83^ 


19M 


IM 


13K 


IIM 


8-M 


10 


2214 


21% 


103^ 


25 


ly 


16 


14M 


12-3^ 


12 


24 


24M 


ny 


29S/8 


9 


19 


17 


12-K 


14 


25 M 


28^ 


IWs 


335,^ 


9 


21 


183^ 


12- 1 


16 


28 


ny, 


153/8 


3834 


2J-^2 


233^ 


2134 


16-1 



256 



Webster Low-pressure Receiver Oil Separators 

These separators, acting as eliminators of oil and condensation and as 
receivers or mufflers, are used chiefly in exliaust steam lines between recipro- 
cating engines and low or mixed-pressure turbines, or as receivers for the in- 
termittent exhaust from groups 
of steam hammers. 

They are of riveted steel con- 
struction, with cast-iron nozzles, 
and, like most of the Webster Oil 
Separators, are equipped with 
hooked steel multi-bafBes. The 
nozzles are of cast iron with flanges 
drilled low-pressure standard. 

The fllustration shows one of 
the many forms of the Webster 
Low-pressure Receiver Oil Sepa- 
rator. The inlet and outlet noz- 
zles may be located to conform 
with any direction of flow of 
steeim. The axis of the sheU may be either horizontal or vertical. 

Inquiries regarding the WelDSter Low-pressure Receiver Oil Separators 
should be accompanied by a sketch showing the proposed location of and 
space available for the separator, the sizes and locations of inlet and outlet 
nozzles and the direction of flow. The inquiry should state the maximum 
amount of steam to be purified. 

Webster Grease and Oil Traps 




Fig. 24-31. The Webster Low-pressure Receiver Oil 
Separator 





Fig. 24-32. The Webster Grease and Oil Trap 

The Webster Grease Trap is for use in draining oil separators on exliaust 
steam lines or on feed-water heaters, or for removing from the course of the 
steam any accumulations of oily drips at other points in the low-pressure 
steam mains or branches. It will operate with equal efficiency under any 
pressure between atmospheric and 15 lb. per sq. in., above. It is not de- 
signed for use under high vacuum conditions. 

As shown in the accompanying sectional fllustration (Figure 24-32) the 
valve mechanism is simple. The discharge orifice is designed to give the 
full area of the inlet opening. The valve piece is conical and closes against 
a sharp-edged seat. 

257 



The ball float and valve chamber are easily reached for quick cleaning 
without disturbing pipe connections. 

Properly installed, the Webster Grease Trap should be provided with a 
bypass in the piping around it; a check valve should be in the Kne beyond 
the outlet and bypass, and an equalizing or vent pipe should be run from 
the top of trap to the exhaust main beyond oil separator. See Figure 24-28. 
Ratings for Webster Grease Traps: Because the mixture to be 
discharged is likely to be more or less viscous and sluggish in movement 

when it is cool it is impossible to rate grease 
traps on a condensation basis. The size of 
grease trap to be selected in any case should 
be that of the drip connection of the oil 
separator which it is to drain. 

Table 24-8. Dimensions of Webster Grease and 
Oil Traps 




A' Size Outlet 



A=Size Inlet 



Number 


A 


A' 


B 


c 


D 


E 


F 


G 


H 


U V 


w 


016 


Va 


Va 


153^ 


1 


8 


15 


414 


31/^ 


2'/^ 


81/^ 


Wa 


Va 


116 


IM 


IH 


19 H 


1^/s 


9 


183/s 


53/R 


3'i/R 


4 


lOK 


7 


1 


216 


2 


2 


2();/8 


\yi 


lOH 


19K 


6^8 


4^2 


m 


12M 


8 


1^2 



Fig. 24-33 



All dimensions in inches and subject to slight variation 



The Webster Suction Strainer 





Fig. 24-34. The Webster Suction Strainer 



The Webster Suction Strainer is used to prevent the passage to 
the vacuum pump of dirt and scale brought down with the condensation 
from a vacuum heating system. The use of this strainer prevents scoring 
of the pump-cylinder lining, valves and piston rods and the serious efficiency 
losses and repair bills that would follow such scoring. The strainer is pro- 
vided with a tapping for the introduction of cold make-up water when same 



258 



is desired and when specially ordered, a spray nozzle is provided to insure 
thorough mixture of cold water and vapor in return. Another tapping is 
provided for a connection to the vacuum gauge and a third plugged outlet 
is for draining the body when the strainer is not in use. The shell and re- 
movable cover are of cast iron with composition gasket in the joint. Com- 
panion flanges, drilled low-pressure standard, are provided for inlet and out- 
let connections. 

The basket is of perforated brass, and has at its top rim a casting in 
which is fastened a handle for hfting out the strainer. The perforations are 
0.043 in. in diameter and of sufficient number to provide a total area twice 
that of the entering pipe. 

The Webster Suction Strainer is to be placed in horizontal piping only, 
and should be set so that the axis of the body will be vertical. Water 
flows to it in the direction of the arrow (see Figure 24-34), and its course 
through the strainer is evident from the sectional view in the same figure . 

During the cleaning process it is customary, if the system must be main- 
tained in operation, to use either the relay pump or the ejector, if there is 
one, and if not, to temporarily run the returns by gravity to the sewer or 
waste, closing the stop-valve in the main return. The entire operation oc- 
cupies but a few minutes. 

Table 24-9. Dimensions of Webster Suction Strainer 

K- No. and Size Bolls 

N Tapped ajid Plugged 

For maximum 

working pressm-e 

of 15 lb. per 

sq. in. 

Fig. 24^35 Top view 

All dimensions in inches and subject to slight variation 





Size A 



Bi 



M 



2 


5^ 


4^/8 


12 


6 


6Vs 


5M 


4M 


4^^x2 


y>. 


Va. 


3 


6^ 


m 


ISH 


iy2 


m 


5M 


6 


4^^x2M 


y?. 


Va 


4 


8A 


^a 


163^ 


9 


105^ 


7% 


TA 


8-^x2M 


y-i 


Va 


5 


9^ 


evs 


185^ 


10 


12K 


8^ 


8M 


8-Mx2M 


y?. 


Va 


6 


lOH 


1^ 


20% 


11 


13H 


9ys 


9y2 


8-Mx2M 


y. 


Va 


7 


12^ 


9A 


25 


12 J^ 


19M 


13 


lOM 


8-Mx3 


Va 


1 


8 


UVs 


9% 


27M 


13)^ 


21 


14>^ 


IIM 


8-Mx3K 


% 


1 


10 


n]4 


11 J4 


^2H 


16 


243^ 


16% 


14M 


12-Kx3M 


% 


1 


12 


21 


12K 


38 


19 


29 


20 


17 


12-Vsxsy2 


% 


1 



Webster Dirt Strainers 

Webster Dirt Strainers are used in steam heating systems to prevent 
dirt from entering radiator traps or traps on drip points, mains or blast 
coils. They provide convenient receptacles for retention and accumulation 
of pipe chips, rust, dirt, etc., where impurities can do no harm and where 
they are easily and quickly removed. 

259 







Class A (Offset) 



Webster Dirt Strainers 



Fig. 24-37. Class B (Straightway) 



Two models are made : Class A with offset and Class B with straight- 
way pipe connections. Both have cast-iron shell and cover, the latter made 
easily removable by means of a yoke and screw. 

The basket is made from sheet brass perforated with 0.043-in. diameter 
holes. The total free area through the basket is several times the area of 
the entering pipe. The sides of the basket are reinforced with strips 
which are continued upward to form a bale handle. This handle not only 
serves to make the basket easily removable but acts as a spring against 
the cover to hold the basket in place. 

The range of types and sizes offers a selection for any service conditions. 

The use of these strainers greatly lessens the amount of attention re- 
quired to keep the system in thoroughly efficient operation and eliminates 
incentive for the neglect always to be expected with dirt pockets composed 
of pipe fittings, which cost nearly as much to make and are never as good. 

Table 24-10. Dimensions of Webster Dirt Strainers, Classes A and B 
Maximum pressure, 15 lb. per sq. in. 

Dimensions in inches and subject to slight variation Class A. — Offset (Fig. 24-38) 

Class A 



Class B 



No. 




I«-H Dia-i 
Fig. 24-38 




018-A 
118-A 
218-A 



Size A 



B 



1 or 1M4M 
IH or 2 6 



Bi 


w-\ c 


D 


E 


F 


G 


15< 


pJsA 


1% 


1% 


6 


2?< 


2^4 


2l^!65^ 


2 


2% 


lii^ 


31/^ 


■>% 


I 


3 


3 


9^ 


4% 



2J^ 
3M 
4M 



Class B.— Straightway (Fig. 24-39) 



Fig. 24-39 



No. 


Size A 


B 


Bi 


B2 


c 


E 


F 


G 


H 


018-B 
118-B 
218-B 


Hor M 
1 orlM 
lMor2 


7M 


2M 


2J^ 
3J4 


5t^ 


3 


6 
9A 


2M 
3H 
4M 


2V2 

4M 



The Webster Vacuum-pump Governor 

The vacuum pump of a vacuum heating system should be as nearly 
automatic in operation as possible. 

The Webster Vacuum-pump Governor automatically controls the admis- 
sion of steam to the pump cylinder or cylinders in proportion to the degree of 
vacuum required. When only part of the heating load is on, just enough 

260 



steam is admitted into the pump to produce the degree of vacuum required. 

When the need is greater, the supply of steam is automatically increased. 

The Webster Vacuum- 
«i3r-r„.. _ pump Governor can be ad- 

justed to control the vacuum 
to any predetermined degree, 
and may be readjusted when 
necesscuy. It is remarkably 
sensitive through a wide range 
of adjustment. 




The Webster 

Vacuum-pump 

Governor 





Fig. 24-40 



Fig. 24-41 



Fig. 24-42 



Size A 



Table 24-11. Dimensions of Webster Vacuum-pump Governors 



Bi 



Fi 



F2 



H 


2% 


\% 


5 


9>^ 


iy2 


lOM 


10^ 


1^ 


2J^ 


23H 


1 


m 


IH 


5 


9J^ 


IVs 


lOM 


11 


2 


2J^ 


241/2 


Ik 


4 


IM 


5 


9J^ 


8 


lOM 


11}^ 


2 


2% 


24^8 


m 


4^ 


IM 


5 


9% 


8^ 


lOM 


1114 


2A 


2K 


2534 


2 


5V2 


IH 


5 


9% 


8K 


lOM 


12 


2^ 


2J^ 


26tV 


2J4 


6% 


Wi 


5 


9% 


lOM 


lOM 


13% 


3M 


2J/8 


28i/2 


3 


Wi 


IH 


5 


9Vs 


n^ 


lOM 


14J€ 


3>^ 


2% 


29^2 


3^2 


8 


IM 


5 


9Vs 


iiM 


lOM 


14^ 


4 


2% 


30 



The Webster Suction Strainer and Vapor Economizer 

This special device, in addition to its function of protecting the vacuum 
pump, has a particular advantage in vacuum heating systems where some 
unusual operating condition results in the return of water to the vacuum 
pump at a high temperature. 

Under such conditions, re-evaporation or transformation of water into 
steam vapor may occur, and the presence of this steam vapor adds to the 
duty of and may interfere with the proper operation of the pump. 

If cold water is constantly required for making up the boiler-feed water 
it can be introduced in the standard Webster Suction Strainer, by the use 

261 



of the Webster spray-head, without increasmg the cost of plant operation. 
The special Webster Suction Strainer and Vapor Economizer is designed 
to meet conditions where cooling water is 
required, but where the use of it as make- 
up water would entail waste. 

The cold water is passed around a 
nest of copper coils and absorbs the heat 
of the steam vapor in the main return. 

This water is not handled by the 
vacuum pump and does not mix with the 
condensation in the main return line, as 
the economizer becomes merely 
tension of the hot-water piping system, 
under the available pressure. 




Fig. 24-43 



Fig. 24-44. The Webster Suction Strainer 
and Vapor Economizer 



Table 24-12. Dimensions of the Webster Suction Strainer and Vapor 

Economizer 









All dimensions in inches and subject to 


slight variation 








Size A 


B 


B' 


C D Di E F G 


J K 


T' 


u 


M 


3 
5 

7 


19^ 
223^ 
28M 


6 

7^ 


22 10 15M lYi 53^ 8=^ 
251^ VlYi 187/8 10 dVi 12 
iWi Uy2 24J4 121^ 7K 19 


6 4^^ X 2M 
8^ S-H X 23/4 
lOM 8-M X 3 


2% 


65M 
693^ 
78 





2G2 




Fig. 21-i5. 
Webster Lift Fitting 



Webster Lift Fittings — Series 20 

Webster Lift Fittings are special devices used in 
pairs at points in vacuum heating systems where con- 
densation is to be hfted to a higher level. The con- 
densation is lifted vertically to a higher level in 
"slugs" on the air-lift principle; the slugs being ob- 
tained by the use of a comparatively small diameter 
vertical return with its lower end submerged in the 
well below the level of the horizontal return which it 
drains. The lower lift fitting allows the condensa- 
tion to accumulate in the well below the inlet connec- 
tion until it seals the vertical passage, thus causing 
a slight reduction of the vacuum on the inlet side and 
forcing the water from the well through the vertical lift pipe to the higher 
level. The upper lift fitting allows the condensation to flow into the 
horizontal return without falling back into the lifting line. 

Lifts of six feet or over should be made in steps rather than all in one 
rise. Steps should be used instead of "drag" lifts through long upwardly 
inclined pipes. In any case, the pipes between lifts must grade toward pump. 

Webster Lift Fittings are a big improvement upon and should be sub- 
stituted for the home-made fittings which in the past have had to be made 
from combinations of ordinary tees or crosses and plugs, because nothing 
better was obtainable. Each Webster Lift Fitting is a unit casting, neat in 
appearance and correctly proportioned for capacity of well and for the area 
ratio of inlet to outlet. The use of these fittings eliminates all the guess- 
work and uncertainty about proper operation. They cost less than combi- 
nations of fittings when the labor cost 
as well as that of the fittings is con- 
sidered. 

Each fitting is provided with a 
clean-out plug for removing any accu- 




^Floor Line 



Fig. 24-16. 

Typical application of Webster Lift Fittings 

(See also Fig. 13-1, page 139) 






LJ 

Fig. 24-47. 
Long screwed 
lift connection 



Fig. 24-48. 

Long flanged 

lilt connection 



26.3 



mulation of dirt or other foreign matter from the hft pocket. The larger 
sizes are flanged and finished and drilled to the low-pressure standard. 




Fig. 24-49 

Table 24-13. Dimensions of Series 
Webster Lift Fittings in inches 



20 








Inlet Outle 










Size 




A 


B 


C 


D 


E 


Drain 


% 


Screwed 


% 


¥>, 


VA 


2=/^ 


234 


v?. 


1 


" 


1 


Va 


Wf. 


3 


3/h 


y?. 


li4 


*' 


\Va 


1 


5M 


•iV-?. 


334 


Va 


W-?. 


*' 


IH 


1 


6tV 


^■h 


4^4 


Va 


2 


** 


2 


li4 


6/s 


4/8 


4/r 




2i/« 


** 


2y. 


I'/s 


8i/s 


5/r 


5 '^8 




3 


Flanged 


3 


2i/^ 


14i4 


9 


9»/8 




4 


" 


4 


3 


17i/s 


10/8 


11^4 




5 


*• 


5 


■iV-?. 


19^/ 


12/, 


121* 




6 


*' 


6 


4 


2P4 


13 /« 


i4.fV 




B 


(( 


8 


41/, 


25 i4 


16^4 


17 




10 


** 


10 


6 


31 /s 


20 /s 


20/r 




12 




12 


7 


34/2 


22/8 


23A 





Close screwed 
lilt connection 

Fig. 24-50 

Table 24-14. Minimum Distance Between 

Centers 



%-in. screwed fittings A = 33^ in. 

1-in. " " A = 3M in- 

IJ^-in. " " A = 41^ in. 

IJ^-in. " " A = Wa in. 

2-in. " " A = 5}^ in. 

2H-in. " " A = 8 in. 



3-in. flanged fittings 

4-in. 

5-in. 

6-in. 

8-in. 
10-in. 
12-in. 



B = lOj^ in. 
B = 13,^ in. 
B = 14,^ in. 
B = 15if in. 
B = 18i^ in. 
B = 22^5 in. 
B = 23if in. 



Webster Receiving Tanks — Plain, Water-control 
and Steam-control Types 

These tanks are used in connection with vacuum steam heating systems, 
to provide a place for storage of the condensation discharged by the vacuum 
pump and for liberation of the air that comes over with this condensation. 
Each type is designed for pressures not exceeding 30 lb. per sq. in., for 
installation in horizontal position, and each type has proper receiving 
capacity and air-hberating surface. 

The Plain Type receives the condensation and air tlirough an end 
opening near the top. The air escapes tlirough a vent in the top of the tank, 
and the water flows by gravity to the bottom outlet and to the feed-water 
heater or other point of disposal. If the rate of flow of returns to tank ex- 
ceeds rate of discharge from tank, the excess overflows through an opening 
on the end near the top. 

The Water-control and Steam-control Types have regulating valves 
which are operated by sink pan and rigging similar to those used to regulate 
the water level in Webster Feed-water Heaters. These two types are also 
provided with water-troughs, to insure best operation of the sink pan. 

The Water-control Type has its regulating valve arranged to automati- 
caUy admit "makeup" at all times when the returns from the heating system 
are temporarily insufficient to keep the water level in the tank at the pre- 



264 





Fig. 24-52. Webster Air-separating 

Tank and Receiver, Steam-control 

Type 



Fig. 24-51. Webster Air-separating 

Tank and Receiver, Water-control 

Type 



determined point. The air is vented to atmosphere, the water flows by 
gravity to the heater or other place of disposal, and any excess of water 
overflows, as with the Plain Type. 

The Steam-control Type, which is used where the boiler or boilers are 
to be fed in proportion to the returns reaching the receiving tank, has its 
regulating valve installed in the steam supply line to the boiler-feed pump. 
With water in the tank at or above the predetermined level, the boiler-feed 
pump is in operation, feeding the returns into the boiler, but when the tank 
level is below normal, the steam to the boiler-feed pump is shut ofi" and the 
pump stopped until sufficient returns collect again. Make-up water, if 
necessary, may be introduced into the tank by hand. The venting of air 
to atmosphere, delivery of water by gravity flow and provision for overflow 
of excess water are the same as in the Plain Type. 

All three types of Webster Receiving Tanks are made from riveted 
flange steel and have flat heads. The Water-control and Steam-control 
Types have removable manhole covers and gauge fittings in one end. Each 
tank is hand-made throughout from best obtainable materials. The sizes 
hsted are standard. Larger sizes can be made upon special order. 



265 



Plain 
Type 



Table 24-15. Dimensions of Webster Receiving Tanks 

Note: Openings will be bushed to suit requirements. All dimensions in inches 



Overflow 



Fig. 24-53 




"^Oullel 



Size 


Inlet 


Outlet 


Air vent 


Overflow 


A 


B 


C 


18x48 
24x72 
36 X 96 


4 
5 
8 


4 
5 
8 


2 
3 


4 
6 


253^ 
3834 


25 
37 
49 


33^ 
6 



Water- 
control 

Type 



^c: D >k D >! Water Regulaling Valve 

-A -I >l< TtB- 



Fig. 24-54 




^Outlet to Healer 



Gauge Glass^^ 









K E >) 














Size 


Inlet 


Outlet 


Air vent Overflow Reg, valve A 


B 


c 


D 


E 


F 


G 


18x48 

24 X 72 
36 X 96 


4 
5 
8 


4 
5 

8 


134 4 1 2534 

2 5 13^ 37^ 

3 6 2 503^ 


30 >^ 

4234 
54^ 


3M 
6 

113-2 


12 
18 
18 


243^ 

mi 


14 
18 

24 


183^ 
23 

2834 



Steam- 
control 
Type 



~D H Pump Governor Valve 

-B- 



Blank Nipple 
.Steam 



OverHow 



Fig. 24-55 




Manhole 



^Outlet to Heater 









K E H 














Size 


Inlet 


OuUet 


Air vent Overflow Gov. valve A 


B 


c 


D 


E 


F 


G 


18 X 18 

24 X 72 
36x96 


I 
5 
8 


4 
5 

« 


134 4 1 2534 

2 5 134 375^ 

3 6 2 503<f 


303-2 

423^ 


33-2 
6 
113^ 


12 
18 
18 


243^ 
363i 

483^ 


14 
18 

24 


18M 

23 

283€ 



For ratings see Table 13-1, page 138 
•2C6 



The Webster Water Accumulator 




Fig. 2 1-56. The Webster Water Accumulator 

This is a cast-iron fitting of oval cross section, designed to accumulate 
condensation for the protection of the diaphragms of pressure-reducing 



Live Steam from Boiler 



WEBSTER 
By-pass with Globe or Anole Valve WATER ACCUMUUTOR X T^^ 'o"" *^3uae Connection 




Straiflht Pattern Pressure 
Reducing Valve 



Fig. 24-57 



valves and similar appa- 
ratus against the heat of 
steam which would de- 
teriorate the diaphragms _j!: 
if brought into direct con- l- 
tact. This application is 
shown in Figure 24-57. 

The Webster Water Accumulator may also be used to provide protec- 
tion for low-pressure steam gauges. 




Fig. 24-58 



i \Bushed lo meet requirements 



>^ 




/<a. 



^ 




^'J 



i^ 



I 



Fig. 2 1-59. Webster Combination Gauges 

Gauges for Webster Systems 
Webster Gauges are of high quality and are furnished in various stand- 
ard forms, and to suit special specifications. The usual outfit furnished 
with Webster Vacuum Systems is a set of two 53^-in. face, nickel-plated 
combination pressure and vacuum gauges, mounted on Monson, Me., slate 
board with Webster System name plate. 

267 



Single combination gauges 
can be furnished, either for 
Vacuum or Modulation Systems, 
in 53^-in. size. 

Single gauges are also fur- 
nished with Webster Hylo Vacu- 
um Sets, as elsewhere described. 

Larger gauges, slate or mar- 
ble boards for three or four 
gauges, or gauges having special 
graduations or marking can also 
be furnished when required. 

The Webster Modulation 

Vent Trap 

This device is installed in 
the low point of the dry-return 
line of the Webster Modulation 
System before the returns flow 
to the boiler or boilers as feed Fig.24-60. 



/Connect to Low-pressure Heatkig Main not lessthan 15 
( distant Irom Pressure-reaulating Valve 



Globe Valve__ 



3/4 X 3/4x1/4 Tee 



As deep as possible 
not less than 4'0" 



Vacuum Gauge g) 





1/2 Globe Valve 
1/2' 



1/2 Globe Valve 

V2 



cj#t=±:fc=1^ 



From Vacuum Pump 
Suction Line 



From WEBSTER 
VACUUM GOVERNOR 



t— 3/4 X 3/4 X 1/2 Tee 
-3/4 Dirt Pocket 
Cap 



Connections for gauges, Webster Vacuum System 



Ceiling Line ' 



Overhead Return 
from Heating Steam 




WEBSTER MODUUTION VENT VALVES 

^^..^--^PiuQ, if Inlet Connection 

7\k^;;^i is not used 



By-Pass required only When 
the Return is larger th^nj 
the Inlet to the Vent Tj^fi 



WEBSTER MODULATION 
VENT TRAP 



J*- By- Pass 



This Distance must not 
be lessthan 30"and as 
much more as possible 
depending on Local 
Conditions 



.Union above 
Water Line ol Boiler 



Water Line of Boiler'~^ 



This Connection 
must be on same \^ 
Centre as Wet Return 



Special Swing 
Check Valve 



2=^tt3 



'Connect into Wet 

Return Main 



,Wet Return near Floor 



1] 



Fig. 21 61. Typical installation of the Webster Modulation Vent Trap 

268 





Fig. 24-62. The Webster Modulation Vent Trap 

water. It affords a simple, dependable method of venting the entrained air 
to atmosphere and of automatically insuring the return of the water^to the 
boiler under fluctuating boiler pressures. The air vent is controlled by an 
internal float mechanism. The valve piece is conical and closes against a 
sharp-edged seat. 



Overhead Return from 
Heating System 



WEBSTER MODUUTION VENT VALVE 



Install Trap so that Interior can 
be removed from Bottom 



This Distance must not be less 
than SO-and as muc,h more 
possible depending on Local 
Conditions 




Fig. 24-63. Typical installation of Webster Modulation Vent Trap No. 0020 

269 



Other means for returning water to the boiler are provided for 
unusual structural features of the building or conditions of use, but for 
the average building to which the Webster Modulation System is adaptable 
the Webster Modulation Vent Trap is used. 

In the illustrations, Figures 24-61 and 24-63, Webster Modulation 
Vent Valves are shown in position at the air outlets of the Vent Traps. 
These valves are always required where it is desired to circulate steam 
below atmospheric pressure at intervals. Where large hot-water genera- 
tors are used, or where a part or all of the radiators are under automatic 
control, the vent valves should be omitted unless vacuum breakers are 
provided on the return lines at the proper places. 

The type of Modulation Vent Trap shown in Figures 24-61, 24-62 and 
24-64 is that which is used for the larger systems. For installations such as 
small residences, the size 0020 Trap as shown in Figures 24-63 and 24-65 
is most often used. Capacity ratings are given on page 240. 



L A-Size of Vent to Air 

-A--Size of Relurns from Hfcating System 





NotevGaugc Gtass furnished 
i L ' on order oniy 

■-^^A' -Size to Boiier 

Fig. 24-64. Dimensions of Webster Modulation 

Vent Trap, Series 20 

(See Table 24-16) 




Fig. 24-65. Dimensions of Webster 

Modulation Vent Trap 

Number 0020 



Table 24-16. Dimensions of Webster Modulation Vent Traps, Series 20, Fig. 24-64 



SIZE 


A 


A' 


A= 


B 


B' 


D 


D' 


F 


F' ^ 


G 


H 


No. 020 


'2 


1 


1 


^Vi 


6>^ 


6% 


Ws 


5^ 


m 


5? 8 


10 


No. 120 


IM 


1J€ 


IM 


9A 


8t 


8 


Ws 


8M 


6H 


834 


153^ 


No. 220 


IM 


IM 


IM 


9^ 


Sii 


8 


4K 


^'A 


6M 


8M 


15^ 


No. 320 


IM 


IM 


IM 


95% 


8^ 


8 


Ws 


8y2 


6M 


8M 


153^ 




Fig. 24-66. Webster 
Modulation Vent Valve VgTjt, TraD 

The Modulation Vent Valve 



The Webster Modulation Vent Valve 
This A'^alve has been specially devised to meet the 
requirement for check against inflow of air to a modula- 
tion system when it is desired to operate at a pressure 
less than atmospheric. This check is provided by the 
seating of a hollow seamless ball which is retained by a 
cage structure as shown in Figure 24-66. 

Due to the very slight weight of the ball and the 
construction of the valve body and seat, a pressure less 
than one oimce per square inch will serve to lift the valve 
from its seat, thus permitting the escape of air from the 



is made in only the 3^^-in. size which 



270 



may be used as a single unit for installations up to 8500 sq. ft. of direct 
radiation or equivalent. For larger installations these valves are furnished in 
multiple units of the necessary number with a fitting such as that shown 
in Figure 24-67. See Table 23-9, page 240. 





For use where two vent valves 
are required 

Fig. 24-67. Multiple-unit Webster Modulation Vent Valves 

The Webster Damper 
Regulator 

The Webster Damper Regulator 
is used with the Webster Modulation 
System and automatically controls the 
opening of the draft door and check 
damper of the low-pressure steam- 
heating boiler. It is extremely sensi- 



Three-valve 
pattern 



Note:-To support Damper Regulate 
use 4-t/^"Rods with Pipe 
Separator and mal<e lengtl 
to suit work, remove /q 
any 4 Bolts to suit 





Yi Connection to Live 
Steam Main 



1'/*" Drain Plugoed 



Fift. 24-69. 
Fig. 24-68. The Webster Damper Regulator Dimensions of the Webster Damper Regulator 

tive and accurate because of the ample diaphragm area and controls the fire 
to maintain the steam pressure always within a few ounces of that for which 
the regulator is set. 

Table 24-17. Power Developed by Webster Damper Regulator 

The following figvu-es, based upon tests with lever in mid-position, afford a comparison with other 
damper regulators having much smaller diaphragms 



Pressure in lb. per sq. in , 

Average puU at end of lever, lb. 



0.5 


1.0 


2.0 


3.0 


4.0 


5.0 


4.125 


8.25 


16.5 


24.75 


33.0 


41.25 



271 



Webster Hylo Vacuum-control Sets 

Each Webster Hylo Set consists of a Webster Hylo Vacuum Con- 
troller, handling vapor and air only, a Webster Hylo Trap, handling water 
of condensation only, Webster Hylo Vacuum Gauges, and when needed, 
Webster Lift Fittings. 

The Webster Hylo Vacuum Controller regulates the vacuum from the 
low to the high vacuum through the action of the diaphragm and pilot 
valve. The vacuum differential, as fixed by the position of the weights on 
the diaphragm lever, may be adjusted to maintain the desired vacuum. 

The Webster Hylo Trap permits condensation to flow from low to 
high vacuum without loss of differential. This trap is of ball-float type, with 
outlet water sealed. 

The Webster Vacuum Gauges indicate the vacuum conditions upon 
both sides of the controller. Special arrangements of gauges and boards 
are furnished for varying requirements. 

Webster Lift Fittings are required where returns must be lifted such 
as the case shown in Figure 15-7, page 177. 




Fig. 24-70 



Table 24-18. Dimensions of Webster 
Hylo Controller 

All dimensions in inches and subject to 
slight variation 



Table 24-19. Dimensions of Webster 

Hylo Traps for 15-lb. Working 

Pressure 

All dimensions in inches and subject to slight 
variation 



[Size A 


B 


C 


D 


F 


G 

214 


H 

1054 


u 


1 


ZVo 


1254 


\\% 


IK 


9H 


ly?, 


Wa 


12 »4 


IWa, 


1^4 


2K 


10% 


10 


2 


5 


12M 


ll'A 


2 


3 


lOM 


10^4 



Number 


A 


A' 


B 


c 


D 


E 


F 

55^ 
6K 


G 

^% 
4K 


H 

2K 


U 

1054 

12M 


V 

6J4 

7 

8 


w 


016 
116 
216 


IM 

2 


H 
IM 

2 


1554 
19J/8 
20Ji 


1 


8 
9 

10^ 


15 

19% 


54 

1 



The ratings are the same as for Webster Heavy- 
duty Traps, as given in Table 23-80, page 239 



272 



The Webster Sylphon Conserving Valve 





Fig. 24-72. The Webster 

Sylphon Conserving 

Valve 



This valve is one of the special devices used in connection with the 
Webster Conserving System where steam is furnished direct from low-pres- 
sure heating boilers which are requhed to supply steam for other pm-poses 
than warming the building, at a constant pressure above that required for 
the heating system alone. It also insures the constant operation of the 
low-pressure steam-driven vacuum pump. 

It is placed in the main steam line from boiler, the steam connection to 
vacuum pump being taken from the inlet side of the conserving valve. The 
pressure for which the conserving valve is set must be built up on the inlet 
side, before the conserving valve will open and allow steam to enter the low- 
pressure heating main. 

In consequence, the vacuum pump will automatically start into opera- 
tion before steam is admitted into the low-pressure heating main. The 
partial vacuum created in the return 
mains and radiators assures quick circula- 
tion as soon as the conserving valve 
automatically opens and permits the 
steam to flow into the main. 

When steam supply is cut off from 
the heating system the pump will continue 
to operate until the condensation is thor- 
oughly drained, assuring the return of all 
of the condensation to the boiler. With 
the types of boiler used with heating 
systems of this design, this is a very 
important matter. See pages 173 to 176. I 7"'"^'""^"° . 

Table 24-20. Dimensions of Webster Sylphon Conserving Valves Fig. 24-73 
All dimensions in inches and subject to slight variation 




Size A 


B 


c 


E 


F 


G 


J 


K 


R 


u 


4 


12 


20 


9 


9Vs 


4>g 


7J^ 


8-^ 


2M 


17J^ 


5 


12 


20 


10 


9Vb 


5M 


8M 


8-M 


2M 


183^ 


6 


13 


31 M 


11 


lOM 


6,^ 


9y2 


8-M 


2M 


nVs 


8 


13M 


31 M 


1314 


llM 


7A 


liM 


8-M 


2M 


24M 


10 


15 


36 ^ 


16 


12^2 


85-8 


14 J4 


12-K 


3,^ 


28^ 



273 



The Webster Low-pressure Boiler Feeder — Series 16 

In connection with heating boilers fed from hydro-pneumatic tanks, and 
under certain other conditions, a Webster Boiler Feeder is useful. This 
device is shown on Page 147, as part of a Webster Hydro-pneumatic System. 




WATER INLET 



EQUALIZING PIPE 



Fig. 21-74. Webster Low-pressure Boiler Feeder 

When the water level in the boiler 
lowers, the ball float opens the feed 
valve and allows the water to discharge 
directly to boiler. 

The valve is of the double-balanced 
type with large orifice area, because of 
the low differential between the tank 
pressure and the boiler pressure. The 
ball float is large enough to give the 
lever without excessive difference of 
water level. 

An important point in the con- 
struction of the boiler feeder is that 
the valve and gear are within the cas- 
ing. There are no outside glands to 
keep tight and any leakage which oc- 
curs is within the body of the device 
and hence into the boiler. 

The working parts are easily ac- 
cessible, but seldom need attention. 




EQUALIZING '''S- 2'l-75. Conventional 

pipe; arrangement of Webster 

Low-pressure Boiler Feeder 



SUPPORT FDR FEEDER 



power required to move the valve 




Fig. 21-76 



Table 24-21. Dimensions of Series 16 Webster Low-pressure Boiler Feeder 
Dimensions in inches and subject to slight variation 



Number 



Bi 



G' 



116 


1 


1 
1 
1 
1 


12H 
12H 
12J4 
123^ 


2 

2 

9 

2M 


253.^ 
25?^ 
25^ 
25?^ 


UV2 

14J/9 


6M 

6M 
6H 


IM 

W2 

IV2 


1}^ 
VA 

2H 


11 ?i 
11?-^ 
11^^ 

113^ 


10 
10 
10 
10 


15^ 
15^ 
15J^ 


216' 


W2 
9 


2 

2 


15 
15 


21^ 
2M 


31^ 
31 J^ 


16K 

i6y2 




2M 
2M 


2Vs 
2% 


133/g 
13?^ 


12 
12 


19 Ji 
19 J^ 


316{ 


2V2 

3 


2V2 

23^ 


19 
19 


3M 
3M 


36^ 

36M 


18J4 


8 
8 


3 

3 


3 

3M 


15 
15 


12 
12 


21 
21 



274 



The Webster High-pressure Sylphon Trap 




Fig. 24-7'; 



The Webster High-pressure Sylphon Trap 



This trap is in many respects like the standard Webster Sylphon Trap 
described on Page 242. The body construction is the same except that the 
position of inlet and outlet opening and the union connection of the inlet 
are reversed. 

As the trap must operate at comparatively high steam pressure with 
resulting high temperature, the thermostatic member or bellows is located 
outboard of the valve. The sylphon bellows, surrounded in this position 
with the cooler vapor from the discharged condensate at atmospheric pres- 
sure, is extremely sensitive to the much higher temperature of the steam, 
and consequently acts quickly and positively to close the valve against steam 
passage through the trap. 

It is pEirticularly important when arranging pipe connections that the 
manufacturers directions shall be specifically followed. 

In consequence also of the higher pressure, the valve piece and the seat 
are constructed of monel metal, which successfully resists wire-drawing and 
its accompanying wear. 

The Webster High-pressure Sylphon Trap is made in three sizes and 
for two pressure ranges — Class 2 for pressure from 15 to .50 lb. per sq. in., 
and Class 3 for pressures to 100 lb. per sq. in. 

Application diagrams for this device are shown in Chapters 18 and 20. 




Fig. 24-78 



Table 24-22. Dimensions of Webster High- 
pressure Sylphon Traps 


SIZE 


A 


B 


c 


D 


1^"— 822 

M —833 

1 —844 


33g" 
4,^ 


2^8 


3M" 

2M 

3M 


2M" 
4H 



27.5 




Fig. 24-79. Webster Hydro- 
pneumatic Tank, with 
Double Control 



Webster Hydro-pneumatic Tanks 

Single and Double-control Types 

Webster Hydro-pneumatic Tanks are used in 
place of open-vent tanks for receiving returns in 
steam heating systems where sufficient head room 
to produce the necessary static head is not available 

for the installation of a plain 
receiving tank. 

The general design is 
the same as that of Webster 
Steam-control and Webster 
Water - control Receiving 
Tanks, except that in the 
Single-control Hydro-pneu- 
matic Tanks the sink pan 
and rigging control the es- 
cape of air through the vent 
pipe, and in the Double- 
control type this feature is 
supplemented by an addi- 
tional sink pan rigged to 
control a water valve in the discharge piping. 

In both Single and Double-control types the air is permitted to escape 
freely until the tank is half filled with condensation, when the vent closes 
and the remaining air is confined. The air vent is open whenever the con- 
densation flows by gravity against the resistance in the outlet connection. 
When the necessary head is greater than that due to the tank being half 
fuU of condensation, the air vent is closed. Further accumulation of air 
and water creates additional pressure until this, added to the gravity head, 
overcomes the resistance and condensation flows tlirough the outlet until the 
water line reaches the middle of tank. Then the air vent opens to permit 
escape of air. When the tank has no gravity head to heater or boiler the neces- 
sary head to overcome resistance in the outlet is by confined pressure only. 
The Double-control Hydro-pneumatic Tank, in addition, has its water- 
control valve arranged to close just before the water level reaches the bottom 
of the tank. The Double-control type serves to prevent admission of air into 
the system, through discharge from the tank, when the pressure in the open 
feed-water heater or boiler may be less than that of the atmosphere. 

Both Single and Double-control Tanks are used under pressure greater 
than the atmosphere and in most instances must be provided with means for 
preventing excessive pressure due to obstruction of overflow. For this pur- 
pose a water-relief valve is provided, which should be piped to an open funnel 
to facilitate observation and correction of unnecessary waste. 

Both Single and Double-control types of tanks are made of riveted 
flange steel plate, have flat heads and are for installation in horizontal 
position. A water-trough running along the top distributes the water and 
assures that sink pans are kept filled with water. 

276 



Manholes and covers and gauge glass fittings Eire regular equipment 
with both types of tanks. Sizes listed are standard. Others made to order. 

Table 24-23. Dimensions of Webster Hydro-pneumatic Tanks 
Openings will be bushed to suit requirements. All dimensions in inches 

Single-control Type 




Size 


Inlet 


Outlet 


Vent valve 


Overflow 


A 


B 


c 


D 


E 


F 


G 


18x48 


4 


4 


% 


4 


29M 


30^ 


10 


12 


24^ 


14 


18 1 


24x72 


5 


o 


IH 


5 


43M 


421^ 


13 


18 


36J4 


18 


22M 


36x96 


(2)8 


8 


Wi 


6 


58 


545^ 


18 


18 


483.^ 


24 


28M 



Double-control Type 




Size 


Inlet 


Outlet 


Vent valve 


Overflow A 


B 


c 


D 


E 


F 


G 


H 


J 


18 X 


48 


4 


4 


% 


4 


29^ 


303^ 


10 


12 


24M 


14 


18 


20 


19K 


24 X 


72 


5 


5 


IH 


5 


43M 


42J^ 


13 


18 


36M 


18 


22% 


22 


2S% 


36 X 


96 


(2J8 


8 


VA 


6 


58 


545^ 


18 


18 


483 8 


24 


28M 


313 s' 


35 



For ratings, see Table 13-1, page 138. 
277 



Webster Expansion Joints 

Webster Expansion Joints are constructed with cast-iron bodies and 
brass-slip sleeves and in both single and double-slip types. 

The body of the Webster Expansion Joint is provided with anchors 
made integral with the body castings for rigid connection to a foundation or a 
bracket. Service connections are provided for greatest convenience in 
tapping the steam main for branch piping. Drip outlets also are provided. 




Fig. 24-82. Class D (at left) 
Webster Expansion Joint 



Fig. 24-83. Class DH (at right) 
Webster Expansion Joint 



Fig. 24-84. Class G (at left) 
Webster Expansion Joint 




Fig. 24-8.5. Class GH (at right) 
Webster Expansion Joint 



278 




Fig. 24-86 



Table 24-24. Class D Webster Expansion Joints for Low-Pressure Steam 

Dimensions (in inches) 



Size 


B 


Bi 


c 


D 


Di 


E 


F 


Fi 


G 


J= 


J 


K' 


M 


m 


6M 


43^ 


13'/^ 


3 


3 


5 


2^ 


015. 
-16 


23 s 


w^ 


1?4 


2- M 


1 


2 


6 


■m 


13M 


3 


3 


6 


2J^ 


3 


2y2 


m 


1% 


2- M 


IK 


2y?, 


6^ 


41/8 


141^ 


3 


3 


7 


3M 


3J^ 


3H 


l»4 


\-% 


2- M 


2 


3 


6Vs 


4/8 


14^ 


3 


3 


7^ 


2Ji 


3J^ 


2% 


IM 


IM 


2- M 


2 


SV?. 


IVi 


41^ 


16 


4 


4 


&y2 


3}^ 


3M 


33^ 


9 





4- Vi 


9 


4 


7^ 


41/, 


16 


5 


5 


9 


4 


4M 


4 


2H 


2/, 


4- J^ 


2/2 


5 


8^ 


4/r 


i-rVs 


5 


5 


10 


41^ 


5}^ 


4^ 


2/^ 


2/^ 


4- J^ 


2/?, 


6 


8M 


4/8 


17M 


6 


6 


11 


5 


5^ 


5 


3 


3 


4- ^ 


2/2 


7 


12^ 


7 


20 j^ 


6 


6 


121^ 


6^ 


6J^ 


534 


3 


3 


4- J^ 


3 


8 


13^ 


7'^ 


21 J^ 


6 


8 


13,1/^ 


7M 


7J4 


6 


5 


3 


4- % 


3/2 


10 


141^ 


7V4 


23^ 


6 


8 


16 


SVs 


8H 


7 


5 


3 


4-1 


4 


12 


15J^ 


8M 


25 K 


7 


8 


19 


m 


9^ 


834 


5 


33/2 


4-1 


5 


14 


ny^ 


934 


28^ 


8 


8 


21 


lOM 


10=4 


8^4 


5 


4 


4^1^ 


6 


16 


1-7H 


9M 


281^ 


8 


8 


233^ 


12 


nVs 


10 


5 


4 


4-1^ 


6 


18 


18 


9^4 


2834 


8 


12 


25 


13M 


13^ 


11 


9 


4 


4-13^ 


6 


20 


18 


9M 


30^ 


8 


12 


271^ 


14)4 


141^ 


12 


9 


4 


4-134 


6 



Maximum working pressure, 15 lb. per sq. in. 

This joint has single slip and maximum traverse of 5 in. and is made 
with a close-grained cast-iron body and brass tubing or cast-brass sleeve. 

Standard equipment includes service and drip connections, anchor plates 
and gland packing. 

Companion flanges are furnished only when specially ordered. 

Flanges are drilled low-pressure standard unless specially ordered 
otherwise. 

279 




1V4 DRIP' 



Fig. 24-87 



Table 24-25. Class DH Webster Expansion Joints for High-Pressure Steam 

Dimensions (in inches) 



Size 


B 


Bi 


c 


D 


Di 


E 


E2 


F 


Fi 


J^ 


P 


K' 


M 


iy2 


63/4 


4?'8 


isi-s 


3 


3 


5 


8M 


2Js 


2il 


is^' 


134 


2- H 


1 


2 


6 


■il/H 


13M 


3 


3 


6 


8H 


2J4 


3 


IM 


IH 


2- M 


114 


'■i'A 


by. 


4^8 


14M 


3 


3 


7 


lOH 


3}-i 


3J^ 


13/f 


\V, 


2- M 


2 


3 


(>ys 


4J/8 


UV2 


3 


3 


7^ 


11 


2V8 


3J^ 


1¥ 


IH 


2- ?€ 


2 


3^2 


7J^ 


4H 


16 


4 


4 


8K 


13 


i'A 


3M 


2 


2 


4^ 3^ 


2 


4 


1V2 


4^2 


16 


5 


5 


9 


12 


4 


4^ 


21^ 


214 


4- Vs 


21/^ 


5 


^Vs 


4^8 


17^ 


5 


5 


10 


14M 


4H 


53^ 


2H 


21/^ 


4- 3^ 


2H 


6 


m 


4i/« 


17K 


6 


6 


11 


15M 


5 


5^ 


3 


3 


4- % 


21^ 


7 


12>^ 


7 


20Vs 


6 


6 


12}^ 


1714 


6^ 


6}4 


3 


3 


4^ K 


3 


8 


13M 


7i4 


22ys 


6 


8 


l^V2 


18^ 


7J^ 


7M 


5 


3 


4- J^ 


m 


10 


14^ 


7^^ 


23}^ 


6 


8 


16 


21 M 


85^ 


8}^ 


5 


3 


4-1 


4 


12 


15^ 


8^ 


25 J^ 


7 


8 


19 


24M 


9?i 


9J^ 


5 


3y2 


4-1 


5 



Maximum working pressure, 125 lb. per sq. in. 

This joint has single slip and maximum traverse of 5 in. and is made 
with a close-grained cast-iron body and brass tubing or cast-brass sleeve. 

Standard equipment includes service and drip connections, anchor 
plates, limit bolts and gland packing. 

Companion flanges are furnished only when specially ordered. 

Flanges are drilled low-pressure standard unless specially ordered 
otherwise. 



280 




: J t ^^%» 



K'=NO. AND SiZE OF CORES M = SIZE OF SERVICE 
CONNECTION^ 



1V4DRIP 




Fig. 24-88 



Table 24-26. Class G Webster Expansion Joints for Low-Pressure Steam 

Dimensions (in inches) 



Size 


B 


C 


D 


D' 


E 


F 


F> 


J- 


J= 


Ki 


M 


ly?. 


ilA 


22K 


3 


3 


5 


2M 


2M 


IM 


IM 


2- Vi 


1 


2 


nys 


22 J^ 


3 


3 


6 


2J^ 


3 


IM 


IM 


2- M 


1)4 


2y?. 


n% 


23H 


3 


3 


7 


3M 


3^ 


IM 


IM 


2- M 


2 


3 


12 j^ 


25M 


3 


3 


7J^ 


2K 


3J^ 


IM 


IM 


2- M 


2 


■iy?. 


12^ 


251^ 


4 


4 


83^ 


334 


3M 


9 


2 


4^ Jl 


2 


4 


13^ 


26M 


5 


5 


9 


3^ 


4M 


2M 


23i 


4^ Ys 


23/2 


5 


13M 


27H 


5 


5 


10 


41^ 


5H 


23^ 


23^ 


4- Ji 


234 


6 


13J^ 


27M 


6 


6 


11 


5 


53-8 


3 


3 


4- K 


2^2 


7 


14}^ 


283^ 


6 


6 


123^ 


6^ 


63^ 


3 


3 


4- Vs 


3 


8 


15 J^ 


31 M 


6 


8 


13H 


6H 


7M 


5 


3 


4^ 3^ 


33^2 


10 


17 


33 J^ 


6 


8 


16 


8 


83^ 


a 


3 


4-1 


4 


12 


18J^ 


36}^ 


7 


8 


19 


9 


9^ 


5 


3}^ 


4^1 


5 


14 


183^ 


37M 


8 


8 


21 


10>^ 


105^ 


5 


4 


4r-iyg 


6 


16 


19^ 


38 J^ 


8 


8 


23^ 


12 


nj^ 


5 


4 


4r-iys 


6 


18 


SOKs 


401^ 


8 


12 


25 


13M 


13}^ 


9 


4 


4-13^ 


6 


20 


22 


44 


8 


12 


27y2 


14 


14}^ 


9 


4 


4^134 


6 



Maximum working pressure, 15 lb. per sq. in. 

This joint has double-slip and maximum traverse of 10 in. and is made 
with a close-grained cast-iron body and brass tubing or cast-brass sleeve. 

Standard equipment includes service and drip connections, anchor 
plates and gland packing. 

Companion flanges are furnished only when specially ordered. 

Flanges are drilled low-pressure standard unless ordered otherwise. 



281 



g Eimrngg^ 




E' 



\% DRIP 



K=NO. AND SIZE OF CORES M =SIZE OF SERVICE 

CONNECTION - 




-(»| 



Fig. 24-89 



Table 24-27. Class GH Webster Expansion Joints for High-Pressure Steam 

Dimensions (in inches) 



Size 



B> 



D> 



El 



Fi 



M 



1J4 


16^8- 


8A 


22S'g 


;^ 


3 


5 


8M 


2V4 


2|* 


l?i 


13-4 


2- h 


1 


2 


163^ 


8M 


22 H 


3 


3 


6 


8M 


21/. 


3 


134 


1% 


2- M 


i-'A 


^^2 


16y2 


8^ 


23K 


3 


3 


7 


103^ 


3K 


■m. 


134 


m 


2- M 


2 


3 


\W2 


9J€ 


25M 


3 


3 


7}^ 


11 


2-/8 


■iV?. 


134 


m 


2- M 


2 


■i'A 


18 


9 


25}^ 


4 


4 


9 


13 


314 


334 


9 


2 


4- Vs 


2 


4 


19 


9}-^ 


26M 


5 


5 


9 


12 


3V« 


414 


21^ 


2i/? 


4- 3^ 


zy?, 


5 


19}^ 


9M 


27}^ 


3 


.T 


10 


14M 


4H, 


51/8 


2J4 


2/. 


4- ^ 


2^2 


6 


19M 


9^ 


27M 


6 


6 


11 


15M 


5 


53/8 


3 


3 


4- 3^ 


2y9. 


8 


23 


11^ 


31 M 


6 


8 


131-^ 


18>i 


63^ 


74 


5 


3 


4^ J^ 


w?. 


10 


241^ 


12^ 


33 J^ 


6 


8 


16 


21^ 


8 


8J^ 


5 


3 


4-1 


4 


12 


25 ?i 


12K 


36M 


7 


8 


19 


24M 


9 


9M 


5 


sy, 


4-1 


5 



Maximum working pressure, 125 lb. per sq. in. 

This joint has double-slip and maximum traverse of 10 in. and is made 
with a close-grained cast-iron body and brass tubing or cast-brass sleeve. 

Standard equipment includes service and drip connections, anchor 
plates, limit bolts, and gland packing. 

Companion flanges are furnished only when specially ordered. 

Flanges are drilled low-pressure standard unless specially ordered 
otherwise. 



282 



Table 24-28. Distance Between Anchor Points and Webster Expansion Joints 
for Various Steam Pressure Conditions 

The following table is recommended as a guide in the design of steam piping for determination of 
the proper points of installation of Webster Expansion Joints. In such design the maximum pressure which 
the pipe line must sustain during acceptance tests or other special conditions must be selected as the " Gauge 
pressure" 



Gauge 
pressure 



Temperature 
difference 
above zero 



Expansion 

Inches 
per 100 feet 



Safe maximum distance in 

feet between anchors 

for single-slip 

expansion joints* 






212 


1.53 


260 


5.3 


227 


1.64 


245 


10.3 


240 


1.73 


225 


15.3 


250 


1.80 


220 


20.3 


259 


1.87 


215 


25.3 


267 


1.93 


210 


30.3 


274 


1.98 


202 


40.3 


286 


2.06 


195 


50.3 


297 


2.14 


190 


75.3 


320 


2.31 


175 


100.3 


337 


2.43 


166 


125.3 


352 


2..54 


160 



*For double-slip joints, the safe distance from the joint to an anchor in each direction may be the distance 
specified for a single joint, provided the body of the double joint itself is securely anchored 

Webster Series 21 Steam Separators 

For working pressures up to 200 lb. per sq. in. 

Webster Steam Separators of 
the standard types for removing 
moisture from live steam, have 
cast-iron corrugated baffles against 
which the steam impinges, causing 
a sudden change in direction of 
flow and consequently freeing the 
steam of the entrained moisture. 

The port openings in every 
Webster Steam Separator are of 
such size as to minimize loss of 
steam pressure from unnecessary 
friction. 

These separators may also be 
used for special purposes, as re- 
moving moisture from compressed 
air, assuring operation of steam 
whistles by removing moisture 
from their steam supplies, etc. 

The material ordinarily used 
in the shells is close-grained cast- 
iron, but special shells of semi- 
steel, cast steel or other material 
can be furnished. 

Gauge-glass fittings and drain 
valves are usual equipment but 
are furnished only as extras when 
ordered. 

283 





Fig. 24-90. Vertical type 




Fig. 24-91. Horizontal type 



Table 24-29. Dimensions of Webster Series 21 Steam Separators 

All dimensions in inches 

Companion flanges and gauge and drain fittings furnished only when specially ordered. Flanges 
are drilled to high-pressure standard unless otherwise ordered 




^ Fig. 24-92. Vertical Type 
Down-flow only 




Dimensions 


Flanges 










Outside 


Bolt 


No. & sizes 


Size 


B 


H 


Drip 


diameter 


circle 


of bolts 


2 


21k' 


7 


k 


6k 


5 


4- k 


W2 


223/^ 


8 


k 


7k 


5k 


4- k 


3 


23 J^ 


9J^ 


k 


8k 


6k 


8- k 


3H 


25^ 


10 '/g 


1 


9 


7k 


8- k 


4 


26M 


lOM 


1 


10 


7k 


8- k 


5 


28H 


13>^ 


1 


11 


9k 


8- k 


6 


30M 


15 


1 


12k 


10k 


12- k 


8 


33 M 


20 


Ik 


15 


13 


12- k 


10 


40M 


23}^ 


Ik 


17 k 


15k 


16-1 


12 


44k 


27k 


Ik 


20k 


17k 


16-lk 



Fig. 24-93. Horizontal Type 








D 


imensions 








Flanges 


Size 


B 


F 


G 


H 


Drip 


Outside 
diameter 


Bolt 
circle 


No. & sizes 
of bolts 


2 


9k 


3k 


12k 


8k 


k 


6k 


5 


4- k 


3 


Ilk 


5k 


14k 


10k 


k 


8k 


6k 


8- k 


4 


13k 


5k 


16 


Ilk 


1 


10 


7 k 


8- k 


5 


14k 


7k 


17 k 


14k 


1 


11 


9k 


8- k 


6 


16k 


8k 


19k 


16 


1 


12k 


10k 


12- k 


8 


20k 


10k 


23k 


20k 


1 


15 


13 


12- k 


10 


24k 


12 k 


26k 


24k 


Ik 


17k 


15k 


16-1 


12 


27 k 


14k 


30 


29k 


Ik 


20k 


17k 


16-lk 



284 



Special Types of Webster Steam Separators 

Working pressures up to 150 lb. per sq. in. 







Fig 24-91 
Class L — Angle Type 
with horizontal outlet 




Fig. 24-95 

Class M— Angle Type 

with bottom outlet 




Fig. 24-96 

Class N — Angle Type 

with top outlet 



Table 24-30. Ratings of Webster Steam Separators 
Pounds per minute at average gauge pressures. Based upon a pipe velocity of 6000 ft. per min. 







Gauge pressures 






Size of 


100 Lb. 


125 Lb. 


ISO Lb. 


200 Lb. 


separator 


per 


per 


per 


per 


m. 


sq. inch 


sq. inch 


sq. inch 


sq. inch 


2 


35. 


43.3 


51.6 


66.6 


3 


78.3 


96.7 


112. 


141. 


4 


140. 


167. 


196. 


250. 


5 


215. 


258. 


300. 


391. 


6 


317. 


383. 


450. 


583. 


7 


433. 


516. 


600. 


783. 


a 


550. 


660. 


800. 


1000. 


10 


883. 


1083. 


1250. 


1580. 


12 


1250. 


1533. 


1800. 


2333. 



285 



CHAPTER XXV 

Specifications for Webster Systems 

THE following specifications cover typical Webster Systems only in a 
general way, and are subject to many variations. It is advised that 
wherever practical a Webster Service Engineer be called into con- 
sultation during the preparation of plans and specifications for Webster 
Systems. 

Specifications for the Webster Vacuum System of 
Steam Heating 

(This specification is written for a system of the usual up-feed type. 
For the variations known as the Webster Conserving System and the Webster 
Hylo System, revised special clauses will be furnished by Warren Webster 
& Company on application.) 

General: (Here specify the general requirements of the contract, such as intent of 
drawings and specifications; verification of measurements; co-operation with other con- 
tractors; foreman; ordinances; permits; protectionof work and buildings; rights reserved; 
extra work; return of specifications and drawings ; payments, etc.) 

Cutting of Floors and Walls : The [building] [heating] contractor will cut all holes 
in floors and walls and provide trenches and covers for piping which may be necessary for 
this work, and at completion make all repairs to floors and walls so cut. 

Scope of Work: This specification is intended to cover a 2-pipe low-pressure heating 
system known as the Webster Vacuum System of Steam Heating. 

It is intended to supply radiation for heating the building to a temperature of .... 

degrees fahi\ when the outside temperature is or a corresponding equivalent difference 

in temperature, with doors and windows reasonably tight. 

Special Apparatus: The basis of this specification being a Webster System, each 
bidder is required to submit his proposal for furnishing apparatus manufactured by Warren 
Webster and Company. 

*Alternate Proposals will be considered for the use of modulation supply valves and 

thermostatic retmn traps of the same supply and return tappings and as made by 

, provided each bidder states in his proposal the sum which will be added to 

or deducted from his main bid in case they are used. 

Standard Apparatus: In addition to the special apparatus, this contractor is to fur- 
nish all other material and labor necessary for the complete work as shown on plans or called 
for in specifications. 

Radiation: All pipe coils must be made up of full-weight [mild-steel] [genuine 
wrought iron] pipe and best gray-cast iron fittings and manifolds. All radiators must be of 

the pattern equal in every respect to that manufactured by 

and must be of the heights and columns shown on plans. They must be of the [steam] [hot- 
water] type. 

(Note: If of hot-water pattern, specify that the radiators "shall be connected with the 
supply at the top and the return at the diagonally opposite lower corner." If of steam 
type, specify that they "shall be provided with eccentric bushings and connected so that 
the bottom of the return connection will be lower than the bottom of the supply connection." 
Where Webster Modulation Valves are to be used, hot-water type radiators should be 
specified.) 



* To be inserted in case the Architect or Engineer desires to obtain, for comparative purposes, an alternate price upon ap- 
paratus of a make other tiian Webster 

286 



Contractors supplying radiation ordered for this work shall, if they be called upon 
to do so, demonstrate to the satisfaction of the owners or their authorized representative, 
that the radiation furnished contains in each section of the different types supplied the 
amount of prime heating surface mentioned in the lists published by the manufactui'ers of 
the respective types. This must be demonstrated by actual measurement and the develop- 
ment of the exposed surface of the sections. 

The heating contractor is to instruct the manufacturer of the radiation that he requires 
same to be thoroughly pickled £md cleaned before shipment and that the outlets are to be 
plugged with loose wooden plugs. The manufacturer must issue his certificate to the con- 
tractor showing that these radiators have been so cleaned. These radiators are to be kept 
plugged until same are connected to the different pipe lines. 

Air-valve tappings are to be plugged. 

Radiators must be tapped or bushed for sizes of supplies and returns as shown on plans. 

Coil Hangers: Overhead radiators are to be himg in special pipe hangers and in no 
case shall these coil hangers be more than 10 ft. apart. 

Wall coils are to have spring pieces and are to be hung on cast or wi-ought-iron plates 
spaced as directed by their manufacturer, screwed to 13^i2-in. strap-iron brackets bent to 
shape, and securely fastened to the walls with two expansion bolts each. Brackets must be 
spaced not over 10-ft. centers. Wall radiators must be hung as directed by manufacturers. 

Straps shall be painted two coats of lead and oil paint of colors as directed by owners 
before radiators are set in place. Owners must be given opportunity to paint walls or ceil- 
ings before radiators are set. 

Return Traps : The return end of every radiator, pipe coil or other form of heating 
unit must be provided with a Webster Return Trap (of the type selected). The size of the 
trap shall be governed by the amount of condensation from the radiation unit as called for 
on plans. The cormections of Webster Return Traps must be made to the approval of 
Warren Webster & Company, who will provide the contractor with service details showing 
approved forms of connection. 

Supply Valves: Each radiation unit must be provided with a Webster Modulation 
Valve connected to the top supply tapping. 

The sizes of supply valves, the radiator tappings and the sizes of horizontal bremches 
from risers to radiators must be as shown on the plans, or as hereafter described in this 
specification. 

Pipe: All low-pressure pipe must be full-weight [mild-steel] [genuine wrought-iron] 

equal to that manufactured by All screwed piping must be fitted 

with occasional flEinged unions. Where supply pipes are reduced in the run, eccentric 
reducing couplings must be used. 

Straighten all pipe, ream all burrs and remove all dirt before erecting pipe or fittings. 
Have all runs plumb and parallel with building. Provide Webster Expansion Joints of the 
types and sizes and at the points shown on plans. Support all pipes securely and in such 
manner as to permit unobstructed movement between anchorages for expansion and 
contraction. 

So far as possible, all horizontal runs must be graded in the direction of steam flow. 

Fittings: All fittings shall be best gray-iron, straight and true and free from blow- 
holes or other defects; equal to those manufactured by Fittings for low pres- 
sure shall be standard weight; those for high pressure shall be extra heavy. 

Valves: All check, gate and globe valves must be equal to those manufactured by 



Heat Mains: From the low-pressure side of pressure-reducing valve run a pipe to 
connect into the exhaust steam main where shown on plans. (Here should follow a descrip- 
tion of the course of the steam main and its branches.) 

Horizontal runs must grade not less than 1 in. in 25 ft. 

Live Steam Connection: Connect a . . -in. line from outlet in live steam main 
(where indicated on plans) to the heating main through the pressure-regulating valve. 

This valve shall be . . . -in. size and equal to that manufactured by , and 

shall be set to reduce the steam pressm'e from ... to (1 lb. per sq. in. or less). 

Provide a 3-valve bypass as shown, the valve in front of the reducing valve to be 

287 



of the globe pattern. Run a "control pipe" as shown. Place a low-pressure gauge and a 
^-in. pop alarm valve set at 10-lb. pressure in the heat main about 10 ft. from the 
discharge of pressure-reducing valve. 

Risers : A system of supply and return risers is to be run as shown on plans. Risers 
are to be run [exposed] [concealed] and are to be of sizes marked on plans. All radiator 
branches must grade back to risers or mains with as much grade as possible, in no case 
less than 1 in. in 5 ft. All connections are to be made with ample provision for expansion 
and contraction and particular care is to be taken thai branches are run without pockets. 

Return Piping: All return risers and branches are to connect into return mains. 
Horizontal return piping must be graded toward the vacuum pump not less than 1 in. 
in 40 ft. 

Dirt Traps : The bottom of all supply connections taken from the heating main must 
be dripped into the vacuum return by means of a cooling leg, a gate valve, a Webster 
Dirt Strainer and a Webster Return Trap of size shown on plans. 

Note : In large installations it is advisable to run a separate gravity drip line and connect drip of 
each riser or drip point of main through iJjj-in. line with gate valve to this Une. The discharge of this 
gravity drip line to be to the feed-water heater through loop seal or to the vacuum return through Webster 
Heavy-duty Trap. 

Dirt Strainers: Provide and connect Webster Dirt Strainers of the sizes specified 
and at the points indicated on the plans. 

Lift Fittings: Where lifts occur in the vacuum return lines they are each to be pro- 
vided with a pair of Webster Lift Fittings of the sizes called for on plans and connected 
according to special service detail furnished by the manufacturer. 

RoiLERs: (Here specify the make, size and type of boiler or boilers required; also the 
equipment required for the complete boiler plant, including smoke breeching, damper 
regulator, gauges, feed pump, injector and any other necessary accessories.) 

Vacuum Pumps: (Here specify the make, size, type and number of pumps required 
"to be furnished upon (concrete or other material) foundations to be provided by this 
contractor." Detail specifications of pumps should describe either the electric-driven type 
(Nash, etc.) or the steam-driven type (Blake-Knowles, Burnham, Marsh, etc.). For steam- 
driven pump, specify "simplex, double-acting type, brass lining, and fitted for hot-water 
service" and that "each pump shall be provided with a forced-feed lubricator of approved 
make and having a capacity of one quart." 

Each pump shall have ample capacity for handling the products of condensation from 
the entire heating system. 

The discharge from steam-driven vacuum pump must be connected to the proper 
tapping in the receiving tank. If discharge outlet is located on the side of the steani 
pump, tap the cover plate above the discharge valves and run ^:4-in. air line, connecting 
to discharge pipe. 

All connections must be properly valved and made complete. 

Suction Strainer: In the suction pipe to the vacuum pump, place a Webster Suction 
Strainer. This strainer must be connected to accord with special service detail furnished 
by the manufacturer. 

Vacuum Governor: In the steam connection to vacuum pump below the lubricator 
there must be placed a . . .-in. Webster Vacuum-pump Governor with 3-valve bypass. 
Same must be connected by means of J'2-in. vacuum line to the suction strainer and also 
to the vacuum gauge on board. Each branch must be provided with a globe valve. 

Gauges: Furnish and erect at convenient position two 53^-in. compound gauges 
mounted on a slate board. Connect one gauge to equalizing line between heat main and 
reducing valve, one gauge to a line connecting vacuum governor with vacuum return at 
suction strainer. All gauge piping to be H-in. and all branches valved. 

Air-separating Tank: Furnish a Webster Air-separating Tank ... in. in diameter 
by . . . in. long. This tank is to be of the type. 

Erect the separating tank as high above the heater as possible, as shown on plans, 
and to it make connections from discharge of vacuum pumps and to feed-water heater 
through long loop seal. 

From top outlet on tank make a vent connection to atmosphere. 

288 



Feed-water Heater: Furnish and erect on foundation one Webster Feed-water 
Heater of sufficient capacity for heating the required feed water to within 5 deg. of the tem- 
perature of the steam entering same. 

The drip from oil separator is to connect to waste hne through a Webster Grease Trap 
with 3-valve bypass and check valve as shown in special service detail. 

The contractor is to make all necessciry stecmi, water and drain connections as shown 
or called for. 

Steam Separator : Furnish and connect Webster Steam Separators of approved type 
to steam lines as shown or called for. 

The drip from bottom of each separator is to be connected into a high-pressure trap 
of approved make. Each trap is to be provided with a 3-valve bypass. The discharge 
lines from these traps are to be connected into the feed-water heater. 

Covering : After all piping and apparatus have been tested and made tight to the 
approval of the [ai'chitect] [engineer] or his representative, the following covering is to be 
applied. (Here specify necessary covering for boilers, heater, separator, and all [specify 
which] piping, valves and fittings.) 

Painting and Bronzing : AH radiators, coils and exposed piping throughout the build- 
ing, after being tested, are to be painted or bronzed as follows : 

All radiators, coil and exposed piping are to be painted one coat of sizing and then 
[bronzed] [painted] [two] coats; color as selected by architect or owner. 

All exposed parts of boiler and heater to be painted two coats of black asphaltum paint. 

Tests: All concealed pipes and risers shall be tested and made tight under an 
hydrauUc pressure of 50 lb. per sq. in. before being covered in. The entire system shall 
be tested and made tight under 10-lb. steam pressure. 

Thoroughly blow out the pipes to free them from all accumulation of dirt, chips and 
other material, making temporary piping connections for this purpose. 

Fuel and Labor: The heating contractor will furnish all fuel and labor required for 
testing and adjusting boilers and apparatus and for drying out covering on boilers (and 
smoke breeching). He will also remove water and ashes resulting therefrom. 

Temporary Setting of Radiators : Upon written request of the [architect] [engineer] 
the contractor shall connect up for temporary heat such radiators as shall be designated. 
These radiators shall afterwards be disconnected, moved, cleaned, and afterwards recon- 
nected permanently. Wall radiators and radiators without leg sections shall be supported 
on wooden blocks. Each radiator is to have two pipe connections and no supply or return 
valves are to be attached at this time. Each bidder will state in his proposal a unit price 
which he will charge for making temporary connections as described above. 

Inspection: This job is to be inspected by a representative of the manufacturer of the 
return traps before acceptance and he shall submit a written report of the same to the Archi- 
tects. 

Guarantee : The contractor must agree to make good at his own expense any defects 
in labor or material furnished by him for this work which may develop within one year 
from the completion of this contract, reasonable wear and tear excepted. 

The entire system when completed is to be tested in the presence of the [architect] 
[engineer] or his representative, and made tight without caulking. The contractor will be 
held liable for any damage to the building or its contents due to leaks or other defects in his 
work which may develop during the period of installation and test. 

Specifications for the Webster Modulation System of 

Steam Heating 

(This specification is written for a large residence. It is, of course, 
subject to modifications and variations for other kinds of buildings, for other 
sources of steam than house boiler, etc., for which revised typical specifica- 
tion clauses will be furnished by Warren Webster & Company on request.) 

General: (Here specify the general requirements of the contract such as intent of 
drawings and specifications; verification of measurements; co-operation with other con- 

289 



tractors; foreman; ordinances; permits; protection of work and buildings; rights reserved ; 
extra work; return of specifications and drawings; payments, etc.) 

Cutting of Floors and Walls : The [building] [heating] contractor will cut all holes 
in floors and walls and provide trenches and covers for piping which may be necessary for 
this work, and at completion make all repairs to floors and walls so cut. 

Scope of Work: This specification is intended to cover a 2-pipe open-return heating 
system known as the Webster Modulation System of Steam Heating. 

It is intended that sufficient radiation shall be supplied for heating the building to a 
temperature of . . . deg. fahr. when the outside temperature is ... deg. fahr. or a 
corresponding equivalent difference in temperature, based upon all doors and windows 
being fitted reasonably tight to prevent excessive infiltration of cold air. 

Special Apparatus: The basis of this specification being a Webster System, each 
bidder is required to submit his proposal for furnishing apparatus manufactured by Warren 
Webster and Company. 

*Alternate Proposals will be considered for the use of modulation supply valves 
and thermostatic return traps of the same supply and return tappings and as made by 

, provided each bidder states in his proposal the sum which will be added to 

or deducted from his main bid in case they are used. 

Standard Apparatus : In addition to the special apparatus, this contractor is to fur- 
nish all other material and labor necessary for the complete work as shown on plans or called 
for in specifications. 

Boilers: (Here specify the make, size and type of boiler or boilers required, specifying 
also the equipment required for the complete boiler plants, including smoke breeching and 
other necessary accessories.) (Indicate what contractor is to build boiler foundation.) 

Note: Boilers and auxiliary equipment must be installed in accordance with Warren Webster & 
Company's standard service details. 

Damper Regulator: Furnish one Webster Damper Regulator for each boiler; to be 
connected in accordance with the manufacturer's standard details. 

Gauges: A special compound gauge for Webster Modulation System is to be installed 
for each boiler. This gauge will be furnished by the manufacturers of the system. 

Radiators: All radiators throughout the building shall be of or equal 

approved make; all radiators to be of the hot-water type with supply tapping at top and 
return tapping eccentric at diagonally opposite lower corner. Radiators to be of the height 
and columns and to contain the surface indicated on plams. In no case is radiation to pro- 
ject above window sill. In connecting all radiators, the inlet end shall be placed next to 
feed risers, if possible. 

The indirect stacks are to be (make and type) cast-iron radiation, to 

be of the size and contain the number of sections as called for on plans. 

The heating contractor is to instruct the manufacturer of the radiation that same is 
to be thoroughly pickled and cleaned before shipment and that the outlets are to be plugged 
with loose wooden plugs. The manufacturer must issue his certificate to the contractor 
showing that these radiators have been so cleaned. These radiators are to be kept plugged 
until they are installed and connected. 

Air valve tappings are to be plugged. 

Radiators must be tapped or bushed for sizes of supplies and returns as shown on plans. 

Hangers : Hangers for indirect stacks are to be strong wrought-iron or pipe supports. 

Enclosures for Radiators: The enclosures and grilles for enclosed radiators will be 
furnished by 

Return Traps: The return end of every radiator, pipe-coil or other form of heating 
unit must be provided with a Webster Return Trap (of the type selected). The size of the 
trap for each radiation unit shall be as shown on plan or called for in specification. The 
connections of Webster Return Traps must be made to the approval of Warren Webster 
& Company, who will provide the contractor with service details showing approved forms 
of connection. 

Supply Valves: Each radiation unit must be provided virith a Webster Modulation 
Valve connected to the top supply tapping. 

* To be inserted in case the Architect or Engineer desires to obtain, for comparative purposes, an alternate price upon ap- 
paratus of a make other than Webster 

290 



The sizes of supply valves, the radiator tappings and the sizes of horizontal branches 
from risers to radiators must be as shown on plans. 

Each overhead radiator must be provided with a Webster Modulation Valve with chain 
attachment. 

Provide a Webster Modulation Extended-stem Valve for each radiator behind a grille. 

Modulation Vent Trap: Furnish and install [one] No Webster Modulation 

Vent Trap for separating the air from the condensation in the heating system. [The] 

[Each] trap is to be vented through Webster Vent Valve[s] placed in the top. 

Pipe : All pipe must be full- weight [mild-steel] [genuine wrought iron] equal to that 

manufactured by All screwed piping must be fitted with occasional 

flanged unions. Where supply pipes are reduced in the run, eccentric reducing couplings 
must be used. 

Straighten all pipe, ream all burrs and remove all dirt before erecting pipe or fittings. 
Have all runs plumb and parallel with building. Allowance for expansion and contraction 
must be provided. Support all pipes securely and in such manner as to permit unobstructed 
movement between anchorages for expansion and contraction. 

So far as possible, all horizontal runs must be graded in the direction of steam flow; 
where this is not possible, the pipe lines shall be materially increased in size as shown on 
plans. 

Fittings: All fittings shall be best gray-iron, straight and true and free from holes or 
other defects; equal to those manufactured by Fittings shall be standard- 
weight. 

Valves: All gate valves must be equal to those manufactured by All 

check valves must be special, of balanced type with vertical seat, and of approved make. 

Fresh- AIR Inlets: Fresh-air inlets for indirect heating are to be taken from openings 
provided in walls. Another contractor will provide heavy copper wire screens having 3/2-in. 
mesh, and sheet metal louvers over the mouth of each inlet. 

Sheet Metal Work: The ducts supplying fresh air to the indirect stacks, the indirect 
stack casings and the hot-air flue from indirect stacks to registers are to be made of gal- 
vanized iron. They are to be properly braced and locked tight to prevent air leakage. 
An adjustable lock quadrant hand damper is to be provided in cold-air connection to each 
indirect stack. 

The metal used for all ducts and flues is to conform to the following gauges: 
Ducts that have one dimension over 48 in., . . . gauge. 
Ducts that have one dimension from 30 to 48 in., ... gauge. 
Ducts that have one dimension from 12 to 30 in., . . . gauge. 
Ducts that have one dimension smaller than 12 in., . . . gauge. 

The indirect stack casings are to be made of . . . gauge iron and are to be built neatly 

around stacks and provided with cleanout doors above and below radiators in bottom or side. 

Registers: The registers for the outlets of hot-air flues from indirect stacks will be 

furnished by ; their installation is included within this contract. 

Steam Piping: From the steam outlets on boiler rise and connect to a steam header 
over boiler. From top of header take branches as shown. The steam lines are to be run 
close to ceiling of cellar with a grade of 1 in. in 25 ft. The branches for risers are to be taken 
from top of mains. Steam header and main are to be dripped to wet drip line where shown. 
Risers : A system of supply and return risers is to be run as shown. Risers are to be 
run [exposed] [concealed], tmd are to be of sizes marked on plans. Unless otherwise noted 
on plans, branches to radiators above first floor are to be run concealed in floor construc- 
tion and branches to first floor radiators are to be run overhead in cellar as close to ceiling 
as possible. All radiator branches are to grade back to risers or mains with as much grade 
as possible, in no case less than 1 in. in 5 ft. All connections are to be made with ample 
provision for expansion and contraction and particular care is to be taken that branches are 
run without pockets. 

Return Piping : All return risers and returns from first floor radiators are to connect 
into overhead return mains. The return mains are to start as high as possible and grade 
toward the Webster Modulation Vent Trap 1 in. in 25 ft. The vent trap (or traps) to be 
located where shown and at least 30-in. above the water line and as much higher as possible. 

291 



[The] [Each] vent trap will be provided with a tapping near the top into which the dry 
return main must be connected, a tapping in the bottom from which a ... in. pipe must 
be run to below boiler water line and connected into the wet return through a horizontal 

swing check valve of make. Make a full size bypass connection around [each] 

vent trap. IVIake a . . .-in. city water supply connection to boiler with check valve and 
cock, also a . . . -in. drain to waste through gate valve from the return header of boiler as 
directed. Check valves are to be installed where shown. 

A wet drip line is to be run on wall near floor as shown, and connected to boiler. To 
this line connect drips of mains, indirect radiators and lines from vent trap as shown. 

Covering: After all piping and apparatus has been tested and made tight to the ap- 
proval of the [architect] [engineer], the following covering is to be applied. (Here specify 
necessary covering for boilers, and all steam, return and drip piping, valves and fittings.) 
Painting and Bronzing : All radiators, coils and exposed piping throughout the build- 
ing, after being tested, are to be [painted] [bronzed] as follows: All radiators, coils and 
exposed piping throughout the building are to be painted one coat of sizing and then 
bronzed or painted [two] coats ; color as selected by architect or owner. 

All exposed parts of boiler to be painted two coats of black asphaltum ptiint. 
Radiators or ducts which are visible through grilles or registers are to be painted two 
coats of dull black. 

Tests: All concealed pipes and risers shall be tested and made tight under an 
hydraulic pressure of 50 lb. per sq. in. before being covered in. The entire system shall 
be tested under 10 lb. steam pressure. The entire system shall be thoroughly washed 
out before final test, wasting condensation to sewer or other point of disposal. 

Cleaning Boilers : Remove safety valve, place inside the boiler a sufficient quantity 
of soda ash to cause saponification of oils and grease. Run temporary overflow pipe to waste, 
from safety valve outlet or from highest point of boiler and start moderate fire so that foam- 
ing of boiler will cause flow of oil and grease to waste, at the same time feeding the boiler 
with water to prevent injury to same. After thoroughly boiling out the boiler, draw the 
fire and when cool draw off all water from the boiler and thoroughly wash same with clean 
water to remove dirt and chemicals. The treatment of boiler should be repeated if water 
line fluctuates abnormally or shows signs of foaming. 

Fuel and Lador: The heating contractor will furnish all fuel and labor required 
for testing and adjusting boilers and apparatus and for drying out covering on boilers (and 
smoke breeching) . He will also remove water and ashes resulting therefrom. 

Temporary Setting of Radiators: Upon written request of the [architect] [engineer] 
the contractor shall connect up for temporary heat such radiators as shall be designated. 
These radiators shall afterwards be disconnected, moved, cleaned, and afterwards recon- 
nected permanently. Wall radiators and radiators without leg sections shall be supported 
on wooden blocks. Each radiator is to have two pipe connections and no supply or return 
valves are to be attached at this time. Each bidder will state in his proposal a unit price 
which he will charge for making temporary connections as described above. 

Inspection : This work is to be inspected by a representative of the manufacturer of 
the return traps before acceptance and he shall submit a written report of the same to the 
Architects. 

Guarantee : The contractor must agree to make good at his own expense any defects 
in labor or material furnished by him for this work which may develop within one year from 
the completion of this contract, reasonable wear and tear excepted. 

The entire system when completed is to be tested in the presence of the architect or 
his representative, and made tight without caulking. The contractor will be held liable 
for any damage to the building or its contents due to leaks or other defects in his work 
which may develop during the period of installation and test. 



292 



CHAPTER XXVI 



Webster Sylphon Trap Attachments 

1. For "Sylphonizing" Webster Traps of Earlier Types 

STEAM heating, like almost every other science, has developed pro- 
gressively tlirough experience. 

Being pioneers in this field Weirren Webster & Co. have had ample 
incentive and opportunity for experimental research and development, 
and have constantly improved their product and methods, discarding and 
abandoning earlier types of apparatus as improved forms were adopted. 
The Webster Sylphon Trap (shown and described on pages 242-5) is 
now generally recognized by leading architects and engineers to be the 
most satisfactory type of device for return line systems. It is in its eleventh 
year of success and the total number in use has passed the million mark. 

Owners of buildings and plants in which old-style Webster Valves are 
in use will be vitally interested in knowing that such valves can be readily 
converted into Webster Sylphon Traps by means of the 
Webster Sylphon Attachments described in this chapter. 
The conversion necessary to brirtg the heating system 
thoroughly up to date can be made at a very moderate cost. 
No breaking or touching of pipe connections is involved, as 
the old valve bodies are utilized. 

The advantages to be derived from the "changeover" 
will be evident from the description of the Webster Sylphon 





^_ " '■»,. i 

Fig. 26-1. The No. 422 Thermostatic Valve in its original form and same valve changed over. 

Pipe connections untouched 
293 



Trap, on page 242, which description will equally fit the earlier Webster 
Valves after they are converted by means of Webster Sylphon Attachments. 
The time required for changing over any valve is only a few minutes. 

Conversion of No. 422 Webster Thermostatic Valves: The 
method of changing over by means of the 5-A-13 Webster Sylphon Attach- 
ment is indicated by the illustrations. 

It is only necessary to remove the old bonnets and interior parts, tap- 
ping the body for the insertion of a new brass seat by means of a tapping 
tool. The Webster Sylphon Trap Attachment may then be inserted and 
the old valve has become a new Webster Sylphon Trap equal in performance 
to the standard Webster Sylphon Traps which are furnished to thousands 
of new customers each year. 

For conversion of Multiple-unit Thermostatic Valves, see page 296. 

Conversion of Webster Motor Valves: This is practically the 
same as with the No. 422 Webster Thermostatic Valve except that a slightly 
different Sylphon Attachment is used. 

The illustrations show the No. 522 M Sylphon Attachments for j/^-in. 
motor-valves of the disc-air-port type. The No. 533 M Attachment for 
^-in. motor-valves is of exactly the same construction. These same 
Sylphon Attachments may be applied to the '03 motor-valves of the pin- 
air-port type where this special type of valve is to be changed over. 

For conversion of Multiple-unit Motor Valves, see page 296. 





Fig. 26-2. Jf-Inch Webster Motor-Valve, Disc- Porl 
Type, in its original form and same valve changed o\er. is 

Pipe connections untouched ^ 

Conversion of No. 422 Webster Water-seal Motors: The 
method of changing over, as illustrated, involves the use of the same attach- 
ment as for changing over the Webster Thermostatic Valve as just de- 
scribed. In the case of the Water-seal Motor, however, the operation is 
simplified through the old body being already tapped for the valve seat. 

It is only necessary to remove the old bonnets and interior parts, and 
insert the new brass seat. The Webster Sylphon Trap Attachment may 
then be inserted and the old valve becomes a new Webster Sylphon Trap. 

For conversion of Multiple-unit Valves, see page 296. 

294 





Fig. 26-3. The No. 422 Water-seal Motor in 
its original form aijd same motor changed 
over. Pipe connections untouched 




Fig. 26-4. No. 5-C-15 Sylphon Attach- 
ment for 522 or 523 Water-seal Trap 
where the discharge rating is low 



Conversion of No. 522 Water-seal 
Traps: The change-over in this instance re- 
quires only removal of the old bonnets and 
interior parts, and inserting the new Webster 
Sylphon Trap Attachments. 

Re-tapping is not necessary for the new 
seat. 

For conversion of Multiple-unit Water- 
seal Traps, see page 296. 

Similar Webster Sylphon Attachments can 
be fiu"nished for all the other sizes of Webster 
Water-seal Traps as follows: 





Fig. 26-5. No. 522 Webster Water-seal Trap in its original form and same trap changed over, 
using 522 Sylphon Attachment for higher discharge rating 



295 



The No. 522 and No. 523 take the same Sylphon Attachment. Another 
attachment applies equally for No. 533 and No. 534. No. 544 and No. 545 
each have an individual attachment. 




rTTi 



/J^ 




A 



rfn 



rfri 




=iM= 



-Unil 



.^ 



\ / 



r m 



rf^ 



jfii 



\ffT\ 



5-Unil 



JQL 



rfti 



rfti 



rBi 



rf?i 



rsx 



6-Unit 



Fig. 26-6. Multiple-unit Thermostatic Valve with No. I Type bodies changed over by means of Webster 

Sylphon Attachments. Pipe connections untouched. Note how intervening openings 

are blanked out by new cap and solid seat 

Conversion of Multiple-unit Webster Valves of Earlier Types: 
On units of radiation beyond the capacity of a single valve it was the practice 

296 



ill the past to recommend and use a Multiple-unit Valve, made up of a 
special body having multiple openings to receive two or more bonnets 
similar in all respects to those used in the standard single-unit valve. 

For changing these Multiple-unit Webster Valves by means of Sylphon 
Attachments, the use of Sylphon Attachments is recommended only for the 
alternate openings in the valve body, the intervening outlets being plugged 
as shown in Fig. 26-6. 

Multiple Valves were made up to 6-unit. It is necessary to deter- 
mine whether attachments are for 2-unit, 3-unit, etc., so that proper num- 
ber of attachments, solid seats and blanking-out caps may be furnished. 

The Multiple-unit Valve, when changed, will have capacity equal to 
(and possibly in excess of) the requirements of the original installation. 



II. For "Sylphonizing" Radiator Outlet Valves of Other Makes 






Fig. 26-7. 5-A Extension Attachments (Five-fold Sylphon bellows) applied to valve bodies of various makes 

297 



A great demand has developed for Webster Sylphon Attachments, 
not only in connection with early types of Webster Valves, but for other 
makes of valves and traps, and in the converting of old gravity systems in 
which the ordinary hand- wheel shut-off valve was employed. 

To meet the requirements of a wide variety of sizes and types of valve 
and trap bodies the Attachments described in the following pages have been 
designed. The principle is the same with each attachment. The variation 
is only in the work of application. 

With the instructions furnished and the tools loaned for the purpose, 
the work of Websterizing, by means of these attachments, is so simple that 
it can be done in a few minutes for each radiator, and so cleanly that there is 
no disturbance or damage to surroundings or furnishings. 

The use of these Webster Sylphon Attachments, properly applied 
throughout the building, will often effect the same advantages as extensive 
changes in piping and at a small fraction of the cost. And further, the 
whole work of change-over can be done without interrupting the operation 
of the system as a whole. 

Series 18 Webster Sylphon Attachments are of two general forms: 

Class A in which the attachment parts are fitted in an extension body 
which screws into the old trap or valve body; and Class C in which the at- 
tachment parts are fitted into a special brass cap which is threaded to fit 
the old valve or trap body. 

The Class A Extension Attachments are made with extension bodies 
to receive 5-fold Sylphon Bellows (symbol 5-A) and to receive 12-fold 
Sylphon Bellows (symbol 12- A). 

The extension bodies of both the 5-A and 12-A classes are made with a 





Fig. 26-8. Typical Class A Sylphon Attachments having extension bodies. Where necessary for securing 
correct final adjustment, a screw fit or push fit seat is used. A typical push fit seat is shown at the right. 

298 





Fig. 26-9. Typical Extension bodies 12-A 

threaded opening at the top to receive a standard cap, but of varying diam- 
eters of the lower part of the body, so that the lower end may be threaded 
to fit the thread of the old body. 

The illustrations show the full series of Extension Attachments from 
5-A-12 to 5-A-27 inclusive. The 12-A Extension Attachments are similarly 
made in sizes 12-A-12 to 12-A-27 inclusive, although the application of only 
two of this type is shown. 

The capacity required as indicated by size of radiator determines 
whether a 5-A or 12-A Extension Attachment should be used. 

It will be noted that the valve stem attached to the Sylphon Bellows 
varies in length with the type of valve body, but is similar in all cases. 

The seat requires a little explanation. It is impractical to use a threaded 
seat, as a constant distance must be maintained from body face to seat face 
and this cannot be done with a threaded seat because of the variations in 
the distance mentioned, which will occur in bodies of same make and size. 

The seat is made to push-fit in the body opening which is previously 
prepared by reaming to the desirable diameter. Final attachment to gauge 
depth to meet any variation in the depth of the valve body is made by 
means of a push-in tool which is loaned for the purpose. 

In the case of ordinary globe or angle valve bodies and in various makes 
of float traps where preparation in this respect was not previously provided, 
the push-fit seat described above provides means to obtain the correct 
final adjustment without difficulty. 

The valve stem is a solid brass rod with a conical taper for seating and 
is of varying length as determined: (1) by the gauge depth of the old body 
from bonnet face to seat, (2) by the diameter of orifice in the seat; and (3) 
by the rating of the radiation unit to which the valve is connected. Where 
necessary to provide greater vapor space through the neck of the extension 
body, the rod is turned down to smaller diameter at such points. 

The Class C Cap Sylphon Attachments are designed for those forms 
of old valve and trap bodies in which the expanding member (Sylphon 
Bellows) and conical valve piece may be placed entirely within the old body 
without the use of an extension body. 

With this class of attachment it is necessary to provide a special cap, 
threaded to fit the existing body, but the design has been standardized so 
that few patterns need be used to meet a wide variety of bodies. 

299 




Fig. 26-10. Typical Class C Sylphon 
Cap Atlachnients placed entirely with- 
in the old bodies and push-fit seats in- 
stalled for correct final adjustment 

At the left is a 5-C Attachment 
(Five-fold Sylphon bellows) 

At the right is a 12-C Attachment 
(Twelve-fold Sylphon bellows) 

Note this special case of a new 
screwed-in seat with a pushed-in fer- 
rule for insuring accurate adjustment 



The Class C Cap Attachments, hke the 
Extension Attachments, are made to receive 
either the 5-fold or 12-fold Sylphon Bellows to fp^ 
which the symbols 5-C and 12-C are given. 

The illustrations above show the applica- 
tion of Class C Cap Attachments to tw o differ- 
ent shapes of valve bodies. 

The description given previously in refer- 
ence to the valve stem and seat for the Extension Attachments, applies 
equally to the Cap Attachmputs. 




300 



CHAPTER XXVII 

Fuel Saving by Preheating Boiler-Feed Water 

WHERE exhaust steam is available and would otherwise be wasted, 
a considerable saving of fuel may be effected by utilizing a direct- 
contact (open) feed-water heater to transfer heat from the exhaust 
steam to the cold feed water. 

The saving amounts to approximately one per cent of fuel for each 11 
deg. increase in the feed-water temperature. This is the figure taken 
for ordinary calculations. 

A more accurate method of computing this saving takes into considera- 
tion the total heat in the steam generated in the boiler, as well as the final 
and initial temperatures of the feed water. 
This formula is 

Total saving in per cent = „ , o'o — t~ ' ^^^ which H= total heat above 

11. ~r oZ to 

32 deg. fahr. per lb. of steam at boiler pressure, t,= temperature of water 

after heating, and t2= temperature of water before heating. 

Table 27-1. Percentage of Total Heat of Steam Saved per Degree Increase in 
Feed-water Temperature for Various Pressures of Saturated Steam 











Gauge 


pressure i 


in boiler— 


-Lb. per sq. in. 








ft . 
S ft 





10 


25 


50 


75 


100 


125 


1.50 


175 


200 


225 


l;S 










Value of H 












1^ 


1150.4 


1160.2 


1169.2 


1178.4 


1184.3 


1188.8 


1192.2 


1195.0 


1197.3 


1199.2 


1200.9 






Per cent saved per d 


egree increase in temperature 






32 


.0869 


.0862 


. 0855 


.0849 


.0844 


.0841 


.0839 


.0837 


.0835 


.0834 


.0833 


40 


.0875 


.0868 


.0861 


.0854 


. 0850 


.0847 


.0844 


.0843 


.0841 


.0840 


.0839 


50 


.0883 


.0875 


.0869 


.0862 


.0857 


.0854 


.0852 


.0850 


.0848 


.0847 


.0846 


60 


.0891 


.0883 


.0876 


.0869 


.0865 


.0862 


.0859 


.0857 


.0855 


.0854 


. 0853 


70 


.0899 


.0891 


.0884 


.0877 


.0872 


.0869 


.0866 


.0864 


.0863 


.0861 


.0860 


80 


.0907 


.0899 


.0892 


.0884 


.0880 


.0877 


.0874 


.0872 


.0870 


.0869 


.0867 


90 


.0915 


.0907 


.0900 


.0892 


.0888 


.0884 


.0882 


.0879 


.0878 


.0876 


.0875 


100 


.0924 


.0916 


.0908 


.0900 


.0896 


.0892 


.0889 


.0887 


.0886 


.0884 


.0883 


110 


.0932 


.0924 


.0916 


.0909 


.0904 


.0900 


.0897 


.0895 


.0893 


.0892 


.0891 


120 


.0941 


.0933 


.0925 


.0917 


.0912 


.0909 


.0906 


.0903 


.0902 


.0900 


.0899 


130 


.0950 


.0941 


.0934 


.0925 


.0921 


.0917 


.0914 


.0912 


.0910 


.0908 


.0907 


140 


.0959 


.0950 


.0942 


.0934 


.0929 


. 0925 


.0922 


.0920 


.0918 


.0916 


.0915 


150 


.0968 


.09.59 


. 0951 


.0943 


.0938 


.0935 


.0931 


.0929 


.0927 


. 0925 


,0924 


160 


.0978 


,0969 


.0960 


.0952 


.0947 


.0943 


.0940 


.0937 


.0935 


. 0934 


.0932 


170 


.0987 


.0978 


.0970 


.0961 


. 0956 


.0952 


.0948 


.0946 


.0944 


.0942 


.0941 


180 


.0997 


.0988 


.0979 


.0970 


. 0965 


.0961 


. 0957 


. 0955 


. 0953 


.0951 


.0950 


190 


0.1008 


.0998 


.0989 


.0980 


.0974 


.0970 


.0967 


.0964 


.0962 


.0960 


.0959 


200 


0.1018 


0.1008 


.0999 


.0990 


. 0984 


.0980 


.0976 


.0974 


.0972 


.0970 


.0968 


210 


0.1028 


0.1018 


0.1009 


.0999 


.0994 


.0990 


.0986 


.0983 


.0981 


.0979 


.0978 


220 


0.1039 


0.1029 


0.1019 


0.1010 


0.1004 


.0999 


.0996 


.0993 


.0991 


.0989 


.0987 



301 



Example: Assume a boiler pressure of 140 lb. per sq. in. absolute, and 
initial and final temperatures of 40 deg. fahr. and 210 deg. fahr. respectively. 
The total saving according to this formula is 14.36 per cent, where by the 
"one per cent for each 11-deg. increase" rule, the saving for the same condi- 
tions figures 15.45 per cent. 

For convenience the results as figured from the more accurate formula 
have been reduced in Table 27-1, to a basis of per cent of saving per degree 
increase of temperature. 

Webster Feed- water Heaters: Webster Feed-water Heaters, for 
obtaining the fuel savings just mentioned and other benefits not so easily 
measured , are made in the following types : 

Series 100, Class B, with overflow seal: The standard type for utilizing 






Fig. 27-1. Series 100 Class B 
Webster Feed -water Heater 



Fig. 27-3. Series 400 Class EBP and 
Fig. 27-2. Series 200 Class EB and geries 500 Class EBPH Webster Feed- 
Series 300 Class EBH Webster Feed- water Heater. Preference Cut-out Type 
water Heater. Standard Type. 
Smaller sizes 





Fig. 27-4. Series 800 Class EF Webster 
Feed-water Heater, Standard Type 



Fig. 27-5. Series 900 Class EFP Webster Feed- 
water Heater. Preference Cut-out Type 

302 



exhaust steam at atmospheric pressure and for a maximum steam pressure 
of 3^-lb. per sq. in. May be operated on either induction or thoroughfare 
principle. 

Series 200, Class EB: The standard type for use in connection with ex- 
haust steam systems under pressures not exceeding 5-lb. per sq. in. Best 
operated on induction principle. 

Series 300, Class EBH: Same as Series 200, Class EB, but suitable for 
pressures up to 10-lb. per sq. in. maximum. Tested to 15-Lb. per sq. in. 

Series 400, Class EBP: Same as Series 200, Class EB, but with inde- 
pendent oil separator large enough to purify all exhaust. Specially designed 
for use with exhaust steam heating or drying systems under pressures not 
exceeding 5-lb. per sq. in. 

Series 500, Class EBPH: Same as Series 400, Class EBP, but suitable 
for pressures up to 10-lb. per sq. in. maximum. Tested to 15-lb. per sq. in. 

Series 800, Class EF: This type is for smaller capacities, 50 to 350 
hp., and is similar to Series 200, Class EB, except that the shell is a one- 



Vent 



4t= 



WEBSTER 
AIR SEPARATING TANK 



Discharge from 
Vacuum Pump 



To Drain 





A ^^ 


Nole:- 




The Area 


of Pipe B 


to be tw 


ce that of 


Pipe A 





-M 



To Heating System 



Multiply Maximum Back Pressure 
carried in Heater by 3 to determine 
least Bimension in Feet 
Water Inlet Valve 




Make up 
Water Supply ' 



To Atmosphere 



Suction Outlet 



Note:- 
With Reciprocating Type Boiler Feed Pumps o 
allow at least 24 inches (as much more as ^ 
practicable) from C.L. of Suction Outlet to u 
Pump Valves. With Centrifugal Pumps 
Consult Pump Manufacturer. , 



To Boiler Feed Pump 



^ 



Drain ' 




x:i 



^^.gX^ 



13 To Sewer 



Fig. 27-6. Webster Feed-water Heater installation in connection with a Vacuum Heating System. Water 
inlet automatically controlled. The heater shown is of the standard type. Any other type of Webster 

Heater would be connected in the same way 



303 



piece casting and is supported by a framework made from pipe and fittings. 
It is suitable for working pressures up to 10-lb. per sq. in. 

Series 900, Class EFP: Same as Series 800, Class EF, but including the 
large size oil separator and the cut-out valve. 

Webster Feed-water Heaters, Standard Type: The heater shell 
as illustrated in this chapter, is made of close-grained cast-iron plates. Web- 
ster Heaters are also made with shells of genuine old-fashioned puddled 
wrought-iron, or of other sheet metals such as flange steel or the so-called 
copper-bearing steels. Wrought-iron heaters are specially recommended 
as they are proof against the minor accidents of operation which fre- 
quently crack cast-iron heaters. 

The heater is easily cleaned, as the interior is accessible without dis- 
tvubing any of the pipe connections. The large hinged doors may be quickly 
opened, and the trays withdrawn. The lower chamber, containing the 



Vent 



Ph 



4t 



WEBSTER 
AIR SEPARATING TANK 



Ife 



Discharge from 
Vacuum Pump 



Note:- 
The Area of Pipe B 
to be twice tliat of 
Pipe A 



To Drain 



-fit 



m^P 



. Exhaust to 
Atmosphere 



To Heating System 



Multiply Maximum Back Pressure 
carried in Heater by 3 to determine 
least Dimension in Feet 
Regulating Valve I Returns Inlet 




Back Pressure 
Valve 



To Atmosphere 



From Source of Water Supply 



Note:- 
With Reciprocating Type Boiler Feed Pumps 
allow at least 24 inches (as much more as . 
practicable) from C.L of Suction Outlet to 
Pump Valves. With Centrifugal Pumps 
Consult Pump Manufacturer. 



To Boiler Feed Pump 



Drain 






^ 




^md^ 



3Ta Sewer 



Fig. 27-7. This W ebster Feed-water Heater installation differs from usual practice in that the make-up 
water supply is manually controlled. A float within the heater operates a valve in the steam-pipe sup- 
plying the boiler-feed pump to stop the pump when the water level is below a pre-deterniined point 



.•?04 



filter, is accessible through the filter doors. Where the doors are bolted to 
the heater body, the shell is suitably reinforced, the faces being machined 
to insure tight joints. 

LOW PRESSURE 

RETURNS INLET jROUGH a WATER SEAL 

HEATIN6 TRAYS 



OIL SEPARATOR 

' EXHAUST 
STEAM INLET 



5CRE1 

PUMP m 



HIGH PRESSURE 




T 



OVERFLOW 
SINK PAN 



SKIMMER FOR 
URFACE BLOWOFf 



OIL 
SEPARATOR DRIP 



OVERFLOW 
OUTLET 



«*-W 



TER SCREENS 



Fig. 27-8. Series 200 Class EB and Series 300 Class EBH Webster Feed-water Heater, Standard Type 

305 



mg 



The water supply to the heater is controlled automatically, the regulat- 

valve being operated by a series of levers connected to an open copper 
sink pan (performing the functions of a float), placed within the heater shell. 

Any dangerous excess of water automatically passes out of the heater 
when the water reaches the overflow level. Except in the case of the 100 
Series, the excess water is automatically passed out through a valve actuated 
in the same manner as the cold water supply-valve, that is, by another open 
sink pan placed within the heating chamber. This valve is normally 
closed, preventing loss of steam. 

The Webster Oil Separator which forms a part of each heater is well 




Fig. 27-9. Series 800 Class EF Webster Feed-water Heater, Standard Type 

303 



known and extensively used as an independent unit for removing oil from 
exhaust steam mains, hence its use in the Webster Feed-water Heater. 

The feed water, entering the heater through the automatically con- 
trolled valve inlet, passes into the water-sealed distributing trough, which 
has two wide, extended lips. The water, overflowing from this trough in 
even sheets, is distributed over a series of oppositely inclined, finely per- 
forated metal trays, arranged one above the other as shown in the illustra- 
tion below. The water in its downward course falls from one tray to the 
other, part of it passing through the tray perforations and the balance 

WATER INLET REGULATING 

LOW 

EXHAUST 
5TEAM INLET 



' BAFFLE 
./WEBSTER 
PREFERENCE 
SEPARATOR 




MMER FOR SURFACE 
BLOWOFF 



DRAIN' , 
SCREEN FOR PUMP 



FILTER SCREENS 



CHAMBER 



FILTER CHAMBER 



Fig. 27-10. Series 400 Class EBP and Series 500 Class EBPH Preference 
Cut-out Type Webster Feed-water Heaters 

307 



falling from the lower edge of the tray to the tray immediately below. 

This method of water travel provides the necessary surface contact for 
the steam and water so that the highest possible temperature is imparted to 
the water, causing a liberation of gases and precipitation of solids. Ample 
space is provided for uniform distribution of steam around the trays. 

By reason of the large storage chamber it is possible to utilize the heater 
as a receiver for condensation from heating systems, dry kilns, heating 
apparatus, etc. Between the level at which the cold water supply-valve is 
closed and the overflow there is ample space for the accumulation and 
storage of such returns. 

The filter is located in the lower compartment of the heater. In this 
settling chamber, opportunity is given for the precipitation and filtration 
of the particles of sediment and impurities and for frequent drainage through 
a quick-opening drain valve. 

The filter bed is commonly composed of coke or other suitable material, 
which is contained between the perforated division screens already mentioned. 
This material can be renewed whenever necessary. 

The large doors at the front allow ready access for charging and cleaning. 

The Webster Preference Cut-out Heater: This type, as may be 
noted from the illustrations, combines a Webster Heater and a large oil 
separator with a cut-out gate valve intervening. The oil separator has 
sufficient capacity to remove the oil from the exhaust steam delivered from 
the engines, pumps and other sources. This arrangement is therefore 
especially desirable where exhaust steam is to be utilized in heating or drying 
systems, cooking kettles or other industrial processes. 

A Webster Grease Trap is used in draining the separator. Steam from 
the engines and auxiliaries should be combined in a common exhaust pipe 
before reaching the heater. This exhaust pipe may enter the separator 
horizontally or vertically, the latter condition being usual with the exhaust 
steam current upward. 

Upon reaching the preference oil separator the steam flows horizontally 
through the baffles, which are of the standard Webster design (see Figure 
27-11), comprising a number of hooked steel plates interposed in the course 
of the steam, causing separation by contact, by change of direction and by 
adhesion. The ports through which the steam is guided and the free 
area through the baffles are especially designed to prevent any considerable 
loss of pressure. 

After passing through the baffles, the steam may pass to the heater, or 
to the outlet into the heating system or other apparatus using exliaust 
steam or to the atmosphere. 

Particularly valuable advantages of the Webster Preference Cut-out 
Heater are: 

1. The considerable saving in piping connections and additional ap- 
paratus accomphshed by its use as compared with the Standard Heater. 

2. The cut-out valve used in the Webster Preference Cut-out Heater 
is most rehable for its piu-pose. When the heater is cut out for internal 
inspection or cleaning, the course of the exhaust steam through the oil 

308 



separator is such that no steam is in contact with the side wall of the heater. 
Steam passes through the separator and on to atmosphere or the heating 
system without warming up the heater body to a degree that would endanger 
or discomfort the man who may have to enter. A thorough clean-out is 
possible at any time without having to wait until the whole plant is shut 
down. 

3. The grease and oil trap too is not integral with the overflow of the 
heater, so that if its outlet becomes temporarily deranged, oil cannot get 
back into the heater through the overflow opening. 




Fig. 27-11. Series 900 Class EFP Preference Cut-oat Type Webster Feed-water Heater 

309 



Table 27-2. Dimensions of Series 200, Class EB, Webster Feed-water Heaters 
For working pressure up to 5 lb. per sq. in. 

Specifications 





Capacity 






Heating trays 


Cubic contents 






Weights, lb. 








Drawing 
no. 








Filter 


Wkg. 
pres. 




No. 


Horsepower * 


Lb. 
mln. 


Area 
sq. ft. 


Ma- 
terial 


Total 
cu. ft. 


Water 
cu. ft. 


Shipping 


Max. 


203 


to 400 


II V 


9247 


12.5 




24.4 


14.7 






2600 


3600 


205 


425 to 650 


9203 


16.5 


o 


40.0 


25.5 






3700 


5400 


207 


675 to 900 


9250 


24.0 


c 


60.0 


40.0 


o 




4700 


7300 


210 


925 to 1.350 


.s ° 


9254 


33.0 


2 


80.5 


52.0 


c 


5700 


9000 


215 


1375 to 1850 


- s 


9252 


51.6 


o ^ 


121.3 


80.0 




■f. 


8000 


13100 


220 


1875 to 2400 


OJ O 


9257 


63.8 


^n 


152.5 


101.0 


"2 


9000 


1.5700 


225 


2425 to 3000 




9256 


82.0 


.5 a 


180.0 


128.1 


s 


S 


10300 


18400 


230 


3100 to 4000 


■s.^ 


22457 


95.7 


240.0 


133.5 


c 
s 

o 


o. 


13000 


21300 


235 


4100 to 5500 


^ g 


13377 


121.5 


.2 


316.0 


140.0 


— 


15000 


23600 


250 


5600 to 7500 




13626 


160.1 


g 
< 


400.0 


179.0 


Q 


in 


20000 


31400 


285 


7600 to 9.500 


4 ° 


22196 


201.5 


482.0 


222 






22000 


36000 


299 


9600 to 12000 


z 


18779 


243.0 




268.0 






25000 


41700 



' One rated horsepower^capacity for heating 30 lb. of water per hour from 40 deg. fahr. 
to a temperatvu-e within 5 deg. of the steam temperature 




,® 


® 

1 

IH 
2 
2 


®|® 


® 


® 


®!® 


® 


203 6 
205 8 
2071 8 
21010 


4 
4 
5 

5 


2}^ 
3 

3K 
3^ 




IH 
2 


2K2K 
32K 
43 
53 


1 
1 

1 
1 


21512 
22014 

225il6 
230,18 


2H 
2H 

3 


64 
6'4 
85 
86 


1 

IK 
IK 


2H 

4 
4 


53 

55 

55 

2-55 


IK 
iH 
IH 


235 20 
25022 
285 24 
299 28 


5 


108 
108 
128 
1210 


2-lH 
2-lH 


5 

5 
5 
5 


2-35 
2-3'5 
2-46 
2-68 


2 



Comb. Vent and 
Vacuum Breaker- 

(D 
® 

Pump Outlet 



Live Steam Drips 




DDQ] 



D 



D 



© Drain"' ' 1^ J^ 



annn 



D 



n D 



No. 


Trays 


Foundation 


rer- 
an 


Dimensions 






No. i Size 


Lg. 


Wd. 


Hgt. 


A A' 


B 


c 


DBF G 1 H 


J 

9 


K j L M , N 


P 

5H 


R 


203 


5 15 x24 


35 


35 SOU 


2fi 


26 


HOV, 


66 


54j^ 65i 4H 


7.iH 18H 


21 H 


21 '4 


25 K 


16 


9 


205 


5 


151^x30^ 


41 


41 


88 


32 


32 


88 


72 


.57=/« 


7K'5K 


7934 


2m 


im 


27 


26'/, 


28M 


19 H 


7K 


8K 


207 


6 


16 x36 


45 


45 


101=^ 


36 


36 


101 H 


84 


69 '4 


7K 


93M 


25 


i-iH 


28 H 


2VH 


34 


21H 


9^8 


U 


210 


12 


10 x40K 


51 


51 


101^ 


42 


42 


lom 


84 


67 M 


7% 


6 


93M 


28 


15H 


3IV2 


31 H 


3/ 


'M% 


8 


10^2 


215 


12 


13}^x46 


57 


57 


115K 


48 


48 


115H 


9fi 


77 VS 


8U 


7 


104 M 


33K 


16 


36 


36K 


41J^'275^ 


8K 


1334 


220 


12 


16Kx47 


69 


57 


115^^ 


4S 


60 


115V^ 


96 


81 H 


SW 


7 


105H'4O 


IS 


ay? 


4b 


47 Mi 


■i-iyn 


10=4 


1334 


225 


24 


17Hx28 


69 


66 


117=4,57 


61) 


]1T'4 


96 


82H 


9 


7K 


106,H 40K 


19% 


42 


42^8 


46'4 


33^/8 


lOH 


16 


230 


18 


I6%%i7 


93 


57 


U5M 


48 


84 


116K 


9(5 


77 


9 


7H 


1051^ 52 


20 


bV 


bb 


53ys 


45/8 


UK 


12H 


235 


24 


15Hx47 


105 


57 


120^ 


48 


96 


120H 


96 


77 


^2'A 


9K 


105K 61 K 


2334 


64 


61 


63 K 


51 H 


12 


1334 


250 


4S 


151^x31 


105 


72 


122K 


63 


96 


122H 


96 


75 


11 U 


\tH 


W7H\61H 


25 '/s 


6b 


67 K 


63H 


51^8 


12 


20 


285 


48 


15^x39 


105 


89 


122M 


SO 


96 


122M 


96 


75 




«K 


107?^ 61J4 


27 


6b 


6VK 


63 Hi 




12 


16 


299 


48 


15)^x47 


105 


105 


124?^ 


96 


96 


124?/8 


96 


75 




8H'107H'61i!i 


4U 


60 


67J4 67)^ 


.... 


12 


■iH'A 



All sizes and dimensions in inches 

Note: The above data (except weights) applies also to Extra-heavy 300 Series Class EBH Heaters for 
working pressures up to 10 lb. per sq. in. 

310 



Table 27-3. Dimensions of 400 Series Class EBP Webster Feed-water Heaters 

For working pressure up to 5 lb. per sq. in. 

Specifications 





Capacity 


Drawing 
no. 

13166 
13188 
13167 
13165 
13171G 


Heating trays 


Cubic contents 


Filter 


Wkg. 
pres. 


Weights, lb. 


No. 


Horsepower * 


Lb. 

min. 


Area 
sq. ft. 


Ma- 
terial 


Total 
cu. ft. 


Water 
cu. ft. 


Shipping 


Max. 


403 
405 
407 
410 
415 


to 400 

425 to 650 

675 to 900 

925 to 1350 

1375 to 1850 


=9'il~-gl 


12.5 
16.5 
24.0 
33.0 
51.6 


^11 

•^.S o 


24.4 
40.0 
60.0 
80.5 
121.3 


14.7 
25.5 
40.0 
52.0 
80.0 


1 

c o 

s = 

o 
Q 


5 lb. 

per 

sq. in. 


3500 
4950 
6700 
8050 
10800 


4500 

6650 

9300 

11350 

15900 



* One rated horsepower =capacity for heating 30 lb. per hour from 40 deg. fahr. to a 
temperature within 5 deg. of the steam temperature 



Returns- 
Inlet 

® 



Drain-' 



Comb. Vent and 
Vacu um Breaker 

© 




Live Steam Drips 



Exhaust Outlet 



DIAGRAM FOR PREFERENCE OIL SEPARATORS 
CLASS H 



[ Inlet 



Cut-out 
Gate Valve 

WEBSTER 

CLASS H 

PREFERENCE OIL 

SEPARATOR 



WEBSTER 

CUSS C 

PREFERENCE OIL 

SEPARATOR 




Exhaust Outlet 
® 




Exhaust Inlet 

® 

Note:- The Table of Dimensions 
below refers to Heaters with 
Standard Equipment, 
Separators smaller or larger 
than Standard will be furnish 
ed if desired. The table at 
right shows sizes of all Prefer 
WEBSTER ^^^^ ^'' Separators which 
V GREASE TRAP can be used with this type 
DIAGRAM FOR STANDARD^Ove^tlow/T^ Heater 

EQUIPMENT ^^ 



•^IZE 


CAPACITY 

LBS. STEAM 

PER MIN. 


DIMENSIONS 


SIZE 
DRIP 


Q 


R 


S 


T 


U 


6 


-16 


S 


11 


13 


9X 


10-X 


1 


S 


80 


9)<f 


12« 


14 


U 


n% 


1 


10 


12.5 


11?:^ 


11% 


17'^ 


115i 


14 


1 


12 


175 


13K 


IbH 


18 


15»fi 


15K 


1 


14 


255 


15 


18 


23 


I'j;*' 


ISK 


IH 


l(i 


335 


ITS 


21 


27;f 


22 If 


22 


w 


IS 


375 


ir% 


24 


29» 


21>4 


23S{ 


IK 


20 


475 


■iOH 


23 Si 


30 5i 


25;<f 


24-X 


lYi 



Fig. 



-13 





Standard 


Connections 


Trays 


Foun- 




o 


Equipment 


























s 


to S 


•o > 
CO > 

6 


tniJ 
1 


® 

10 


® 
1 


® 

4 


® 
21/, 


® 


® 


® 
■2Vo 


® 
2 1/9 


® 


d 


Size 


5 


35 




403 


10 


5 


15 x24 


35 


80^4 


405 


12 


8 


1 


12 


Wo 


4 


3 


1 


IH 


3 


21/4 




5 


1514^30 Vs 


41 


41 


88 


407 


16 


8 


iH 


16 


2 


5 


31/4 


1 


9 


4 


3 




6 


16 x36 


45 


45 


101^ 


410 


18 


10 


W9. 


18 


9 


5 


31/4 


1 


9 


5 


3 




12 


10 x403^ 


51 


51 


101^ 


415 


20 


12 


IVi 


20 


2K2 


6 


4 


1 


2H 


5 


3 


1^' 


12il3i/4x46 


57 


.1. 


1151/^ 





Dimensions 


c 

V 
CO 


A 


A' 


B 


c 


D 

545/R 


E 

6% 


F 


G 


H 


J 

9 


K 


L 


M 


N 





P 


V 


403 


26 


26 


803/j- 


66 


7314 


18 14 


213/., 


1714 


2514 


16 


534 


9 


lOH 


405 


32 


32 


88 


72 


57 yk 


7 1/4 


5H 


79^4 


2114 


1114 


27 


2014 


2834 


1914 


714 


8M 


IIM 


407 


3b 


36 


101 5/g 


84 


691/4 


714 


6 


9314 


25 


133/, 


2814 


221/2 


34 


2114 


914 


11 


11^2 


410 


42 


42 


101 ?/R 


84 


67 W 


r'/. 


6 


9314 


28 


1514 


3114 


2514 


37 


2454 


8 


101/2 


13 


415 


48 


48 


1151/8 


96 


771/5 


8 1/2 


i 


10434 


33I/4' 


16 


36 


281/2 


4114 


27^ 


8J4 


13^ 


14 



Note: The dimeusions aud data above, except weights, may be used also for the 500 Series Class EBFH 
Extra-heavy Pattern Webster Feed-water Heaters 

311 



Table 27-4. Dimensions of 900 Series Class EFP Webster Feed-water Heaters 

For working pressure up to 10 lb. per sq. in. 
Specifications 





Capacity 


Drawing 
no. 


Heating trays 


Cubic contents 


Filter 


Wkg. 
pres. 


Weights, lb. 


No. 


Horsepower* 


Lb. 
min. 


Area 
sq. ft. 


Ma- 
terial 


Total 
cu. ft. 


Water 
cu. ft. 


Shipping 


Max. 


900 
901 
9011-^ 
902 


to 90 

95 to 150 

155 to 225 

230 to 300 


No. of lb. 
per n]in.= 
Yi of rated 
horsepower 


17198 
16837 
16724 
17203 


4.5 

5.0 
5.6 
9.0 


American 
ingot iron 
or copper 


7.1 

9.8 

11.6 

16.4 


4.2 

5.9 

7.3 

11.08 


& o 


c. 


1675 

1780 
2200 
2700 


1925 
2140 
2600 
3425 



Returns 
InletX 

© 



©Comb. Vent and 
Vacuum Breaker 



' One rated horsepower = capacity for heating 30 lb. per hour from 40 deg. fahr. to a 
temperature within 5 deg. of the steam temperature 



DIAGRAM FOR PREFERENCE OIL SEPARATORS 




DIAGRAM FOR STANDARD EQUIPMENT 



Nole:- 
The Table of Dimensions - 
below refers to Heaters 
Ij with Standard Equipment. 
^Separators smaller or 
larger than Standard wil 
be furnished if desired. 
The table at right shows sizes of all 
Preference Oil Separators which 
can be used with this type Heater 



SIZE 


CAPACITY 
LBS. STEAM 
PER MIN. 


DIMENSIONS 


SIZE 
ORIF 


Q 


R 


S 


T 


U 


3 


11 


0^6 


5V 


7^ 


6« 


b^ 


X 


4 


20 


liJi 


7'4 


9X 


7% 


V4 


'i 


5 


32 


7»6 


9 


UM 


<S 


9 


1 


6 


40 


S 


11 


13 


n 


lOY 


1 


8 


80 


9K 


12K 


14 


11 


11 V 


1 


10 


125 


UV 


14X 


Yl% 


14« 


It 


I 



Fig. 27-14 





standard 
equipment 








Connections 






Trays 


Foun- 
dation 




Size 


© 


® 


® 


® 


® ® 


® 


® 


® 


6 


Size 


^ • 


no. 


Size 
sep'r 

Size 
valve 




5 


5 
•0 


ja 


900 


4 


3 


Va 


4 


1 


9 


1V2 


H ' IM 


IH 


IK 


H 


4 


10x16 


26 


23 


62 


901 


6 


4 


1 


6 


1 


m. 


2 H .Wi 


I 'A 


ly?. 


1 


4 


10x18 


28 


25 


68 K 


9Q\y? 


8 


4 


1 


8 


1 


3 


2 1 K 


l'4 


ly?, 


ly? 


1 


4 


10x20 


28 


27 


721/, 


902 


8 


5 


1 


. 8 


1 


3 


2 ;M 


IM 


2 


1^ 


1 


4 


14x23 


30 


30 


79 

















Dimensions 


















Size 
no. 


A 


A' 


B 


C 


D 


E 


F 


G 


H 


J 


K 


L 


M 


N 





P 


900 
901 

901 K 
902 


16 
18 

20 
223-4 


18 
20 
20 

22 M 


62 
68K 

723^ 
79 


43 M 
47 M 
51 
56J^ 


48 

54?.^ 
581^ 
63^8 


20H 

23 

23 

24 J^ 


55M 
61 M 
65M 

71^8 


SVs 
5 


18^ 
19 M 
19}^ 
21 


14 
13 

13M 


9M 


9M 

lOM 

12M 


10^ 
113^ 

12K 


3M 
3K 

4K 
5 


57 

63J^ 
67^ 
73 Ji 


8 

9 

9 

10 



All sizes and dimensions in inches 
312 



Table 27-5. Dimensions of Series 800, Class EF, Webster Feed-water Heaters 

For working pressure up to 10 lb. per sq. in. 
Specifications 





Capacity 


Drawing 
no. 


Heating trays 


Cubic contents 




Wkg. 
pres. 


Weights, lb. 


No. 


Horsepower * 


Lb. 
. min. 


Area 
sq. ft. 


Ma- 
teria! 


Total 
cu. ft. 


Water 
cu. (t. 


Filter 


Shipping 


Max. 


800 
801 
801 J4 
802 " 


to 90 

95 to 150 

155 to 225 

230 to 300 


= II ^ ^ 

4— . *J O 

O C CC D. 
.•■='- <U 

o e=„ 2 
Z S3 ° 2 

a — 


17045 
16660 
16661 
16662 


4.5 
5.0 
5.6 
9.0 


American 
ingot iron 
or copper 


7.1 

9.8 

11.6 

16.4 


4.2 

5.9 

7 3 

11.08 


-73 




1125 
1450 
1700 
2200 


1400 
1850 
2200 
2900 



* One rated horsepower = capacity for heating 30 lb. of water per hour from 40 deg. fahr. to a 
temperature within 5 deg. of the steam temperature 





Connections 


No. 


® 


® 


® 


® 


® ® j® ® ® 


800 
801 
801 K 
802 


3 
4 
4 
5 


1 

1 
1 

1 


2 

2}^ 
3 
3 


m 

2 
2 
2 


iH'l>4l'!l'4 H 
Jj lU I'.IU H 
h l'4l'ill2 M 

% 1M2 IH H 



Returns Inlet 
® 



Cold Water Inlet 

Comb. Vent and. 
Vacuum Breaker 

© 



Pump Outlet 
® 



Live Steam Drips ( 

Oil Separator 
Drips 



Pop Alarm Valve 



Exhaust Inlet 

® 




Fig. 27-15 



Drain 





Trays 


Water line 




1 ilter 
















Dimensions 














No. 






Cn 




























No. 


, Size O'er Pow. Rec. 


Th. 
6 


At. 
2.0 


ft. 
.9 


A 

16 


A' 

18 


B 

62 


C D 


£ 

20;^ 


F 

55K 


G 

3H 


H 

18V? 


J 

14 


K 

7K 


L 

9% 


M 

lOV^ 


N 
3H 





800 


4 


i 10x16 


39K 35H32H 
44MI38M 35H 


43 V^ 


48 


57 


801 


4 


i 10x18 


6 


2.5 


1.2 


18 


20 


68H 


47M 


54 J1 23 


Hl»/f 


■m 


IHV, 


171/8 


9V« 


WH 


nvs 


m 


63 V, 


801M 4 


10x20 


48H 42M 35H 


6 


2.8 


1.4 


20 


20 


V2H 


51 ■58K 23 


65 i'. 


*■'/, 


19J/, 


ITA 9H 


10»4 


nv. 


4J1,73!^ 


802 4 


14x23:551^ 4934 3651 

1 


6 


3.6 


1.8 


22M 


22M 


79 


56K,63^f 24K 


71H 


5 


21 


19J<j 91^ 


12M 


12^8 


5 74 



All sizes and dimensions in inches 



The Webster-Lea Heater Meter: This apparatus combines the 
Webster Feed-water Heater of the rectangular cast-iron type, with the 
Lea V-Notch Recording Meter so arranged that both may be operated in 
combination or either independently of the other. 

Besides heating the boiler feed water to the boiling point, this apparatus 
indicates the actual amount of boiler evaporation. Its continuous meter 
records show up careless or improper firing methods, leakage, condensation 
due to poor installation, inferior coal and in other words, act as a check upon 
the general efficiency of the entire boiler plant. 

The charts (Fig. 27-17) can be integrated by means of a standard 
planimeter, and an integrating attachment giving the total flow for any period 
is supplied. The readings from the integrating attachment indicate approxi- 
mately quantities of water which have passed over the weir. 



SI.'? 



aa=:M 




Fig. 27-16. Typical Webster-Lea Heater Meter 

Where it is desired to have a record of the feed-water temperature on 
the same chart with the meter record, a special attachment can be fitted to 
any standard instrument. The meter chart and drum are made wider to 
provide 23/^ inches for temperature calibrations. This space has 25 equal 
divisions calibrated in any specified 50 or 100-deg. interval. 



^^^.'■^.i.!,- 






■ -- ■..v--u' >lKn^lvVv*'^Uu.;H,| 




Fig. 27-17. Typical chart from a Webster-Lea Heater Meter 



Part III— Addenda 

CHAPTER XXVIII 

Miscellaneous Useful Information 

THE tables in the following pages cover many subjects for which the 
Heating Engineer must have readily available data. They have been 
selected after careful consideration and will be found reliable and suf- 
ficiently accurate in every respect to meet the requirements of good practice. 
The tables on any subject can be readily located by reference to the 
back of the book, where they are included both in the general index and 
the special index of tables. 



Table 28-1. Diameters and Weights of Seamless Brass and Copper Tubes 
Iron Pipe Size and Plumber's Size 

Iron pipe size 





Regular 








Extra heavy 




Diameter, in. 


Weight in 
pounds per foot 


Iron 
pipe 
size 


Diameter, in. 


Weight in 
pounds per foot 


Outside 


Inside 


Brass 


Copper 


Outside 


Inside 


Brass 


Copper' 


.405 


.281 


.246 


.259 


H" 


. 105 


.205 


. 3.53 


.371 


.540 


.375 


.437 


. 459 


H" 


. 540 


. 294 


.593 


.624 


.675 


.491 


.612 


. 644 


%" 


.675 


.421 


.805 


.847 


.840 


.625 


.911 


.9.58 


Vi' 


.840 


.542 


1.191 


1 . 2.53 


1.050 


.822 


1.235 


1.298 


K" 


1 . 0.50 


.736 


1.622 


1.706 


1.315 


1.062 


1 . 740 


1.829 


I" 


1.315 


.951 


2.386 


2.509 


1.660 


1.368 


2.557 


2.689 


IK" 


1.660 


1.272 


3.291 


3.460 


1.900 


1.600 


3.037 


3 193 


1 Vi" 


1.900 


1.494 


3.986 


4.191 


2.375 


2.062 


4.017 


4.224 


«>" 


2.375 


1 . 933 


5 . 508 


5.791 


2.875 


2.500 


5.830 


6.130 


2J--2" 


2.875 


2.315 


8.407 


8.839 


3.500 


3.062 


8.311. 


8 741 


3" 


3. 500 


2.892 


11.24 


11.82 


4.000 


3. 500 


10.85 


11.41 


3^" 


4.000 


3.358 


13.66 


14.37 


4. 500 


4.000 


12.29 


12.93 


4" 


4.500 


3.818 


16.41 


17.25 


5.000 


4.500 


13.74 


14.44 


iV2" 


5.000 


4.250 


20.07 


21.10 


5.563 


5.062 


15.40 


16.19 


5" 


5. 563 


4.813 


22.51 


23.67 


6.625 


6.125 


18.44 


19.39 


6'; 


6.625 


5 . 7.50 


31 . 32 


32.93 


7.625 


7.062 


23.92 


25.15 


7" 


7.625 


6.625 


41.22 


43.34 


8.625 


8.000 


30.05 


31 . 60 


8" 


8.625 


7.625 


47 . 00 


49.92 


9.625 


8.937 


36.94 


38.84 


9" 










10.750 


10.019 


43.91 


46.17 


10" 










Plumber's size 










.654 


.521 


.452 


.475 


Vs" 




.768 


.631 


..554 


.583 


K" 










.875 


.728 


.682 


.717 


H" 










1.000 


.836 


.871 


.916 


1" 


* Amei 


ican Brass Co 






1 . 245 


1.060 


1 . 233 


1.297 


1J4" 










1.508 


1.311 


1 . 606 


1 . 689 


W2" 










1.756 


1 . 564 


1 . 84 4 


1.939 


m" 










2.007 


1.815 


2.123 


2.232 


O" 











.•51.5 



Table 28-2. Dimensions of Standard Wrouglit-Iron Pipe"'* 

Black and galvanized for temperatures up to 450 deg. 

lJ4-In. and smaller proved to 300 lb. per sq. in by hydraulic pressure 
IJ^-In. and larger proved to 500 lb. per sq. in. by hydraulic pressure 



Nominal 
diameter 


Actual 
outside 
diameter 


Actual 

inside 

diameter 


Inside 
circum- 
ference 


Outside 
circum- 
ference 


Length of 
pipe per 

sq. ft. 
of inside 
surface 


Length of 
pipe per 
sq. ft. of 
outside 
surface 


Inside 
area 


Outside 
area 


Length of 
pipe con- 
taining one 
cubic foot 


Weight 
per ft. 


In. 


In. 

0.405 
0.54 
0.675 
0.84 


In. 

0.270 
0.364 
0.494 
0.623 


In. 

0.848 
1.144 
1 . 552 
1.957 


In. 

1.272 
1.696 
2.121 
2.652 


Ft. 

14.15 

10.50 

7.67 

6.13 


Ft. 
9.44 
7.075 
5.657 
4.502 


In. 

0.0572 
0.1041 
0.1916 
0.3048 


In. 

0.129 

0.229 

0.358 

0.554 


Ft. 

2.500. 

1385. 
751.5 
472.4 


Lb. 

0.243 
0.422 
0.561 
0.845 


1 


1.05 
1.315 
1.66 
1.90 


0.824 
1.048 
1.380 
1.611 


2.589 
3.292 
4.335 
5.061 


3.299 
4.134 
5.215 
5.969 


4.635 
3.679 
2.768 
2.371 


3.637 
2.903 
2.301 
2.01 


0.5333 
0.8627 
1 . 496 
2.038 


0.866 
1.357 
2.164 
2.835 


270. 

166.9 
96.25 
70.65 


1.126 
1.670 
2.258 
2.694 


9 

3 

3J^ 


2.375 
2.875 
3.50 
4.00 


2.067 
2.468 
3.067 
3.548 


6.494 

7.754 

9.636 

11.146 


7.461 

9.032 

10.996 

12.566 


1.848 
1 . 547 
1.245 
1.077 


1.611 
1.328 
1.091 
0.955 


3.355 
4.783 
7.388 
9.887 


4.430 

6.491 

9.621 

12.. 566 


42.36 
30.11 
19.49 
14.56 


3.600 
5.773 
7.547 
9.055 


4 

4K 
5 
6 


4.50 
5.00 
5.563 
6.625 


4.026 
4.508 
5.045 
6.065 


12.648 
14.153 
15.849 
19.054 


14.137 
15.708 
17.475 
20.813 


0.949 
0.848 

0.757 
0.63 


0.849 
0.765 
0.629 

0.577 


12.730 
15.939 
19.990 
28.889 


15.904 
19.635 
24.299 
34.471 


11.31 
9.03 

7.20 
4.98 


10.66 
12.34 
14.50 
18.767 


7 

8 

9 

10 


7.625 
8.625 
9.625 
10.75 


7.023 

7.982 

9.001 

10.019 


22.063 
25.076 
28.277 
31.475 


23.9.54 
27 096 
30,433 
33.772 


0.544 
0.478 
0.425 
0.381 


0.505 
0.444 
0.394 
0.355 


38.737 
50.039 
63.633 
78.838 


45.663 
58.426 
73.715 
90.762 


3.72 
2.88 
2 26 
1.80 


23.27 
28.177 
33.70 
40.06 


11 

12 
14 
15 


12.00 
12.75 
14.00 
15.00 


11.25 
12.000 
13.25 
14.25 


35 343 
38.264 
41 . 268 
44.271 


37.699 
40.840 
43.982 
47.124 


0.340 
0.313 
0.290 
0.271 


0.318 
0.293 
273 
0.254 


98.942 
116.535 
134.582 
155.968 


113.097 
132.732 
153.938 
176.715 


1 . 455 

1 . 235 

1.069 

.923 


45.95 
48.98 
53.92 
57.89 


16 
18 
20 


16.00 
18.00 
20.00 


15.25 
17.25 
19.25 


47 . 274 
53.281 
59.288 


.50.265 
56. 548 
62.832 


0.2.54 
0.225 
0.202 


0.238 
212 
0.191 


177.867 
225.907 
279.720 


201.062 
254.469 
314.160 


.809 
.638 
.515 


61.77 
69.66 

77.57 



* Walworth Manufacturing Company 

Table 28-3. Standard Pipe Threads (Briggs Formula) 



Taper of pipe end = J^-in.perft. = ^-in. per in. 
Depth of thread (D) = 0.8 x no. of threads per in 



I Perfect Bottom 

r<-Fl3t Top and Bottom->t^— but — ^ Perfect Thread Top and Bottom 

i— f^3Lrop_^j_ 




h;2Tlireads->« — F-(0.8 Dia.+4.8) ) 









^°.S 


"1 ft c E 


- -d 






«'S.S 


is- 
pe 
nto 
in. 


Norain 

insid 

diam. 

pipe, i 




«'2 ^ 
— f5 ft 

"-a 


« o cl 

5|| 


•Oft 

2 o ? c 
o a oj'S 


o C.2 ft 
ei'~-aft 


Ot3 C 

o a> M 

«|ft 


5 "-I 


C O Kl 

St: 4* 
Oil 




'A 


27 


0.393 


0.334 


0.19 


3 


8 


3.441 


3.241 


0.95 


H 


18 


0.522 


. 433 


0.29 


3J^ 


8 


3.938 


3.738 


1.00 


Yi 


18 


0.656 


. 568 


0.30 


4 


8 


4.434 


4.234 


1.05 


Vi 


14 


0.815 


0.701 


0.39 


4>^ 


8 


4.931 


4.731 


1.10 


% 


14 


1.025 


0.911 


0.40 


5 


8 


5.490 


5.290 


1.16 


1 


UJ^ 


1.283 


1 144 


0.51 


6 


8 


6.546 


6.346 


1.26 


IM 


IVA 


1.626 


1 . 488 


0.54 


7 


8 


7., 540 


7'. 340 


1.36 


IJ^ 


wVi 


1.866 


1.728 


0.55 


8 


8 


8.534 


8.334 


1.46 


2 


WYi 


2.339 


2.201 


0.58 


9 


8 


9.527 


9.327 


1.57 


2^ 


8 


2.819 


2.619 


0.89 


10 


8 


10.645 


10.445 


1 68 



316 



Table 28-4. Dimensions of Black and Galvanized Wrought-Iron Pipe 





Extra strong 




Double extia strong 




Size 


Diameters 




Weight 


Diameters 




Weight 








Thickness 


per foot 
Plain ends 






Thickness 


per foot 
Plain ends 




External 


Internal 


External 


Internal 


Vs 


.405 


.215 


.095 


.314 










H 


.540 


.302 


.119 


.535 










Vs 


.675 


.423 


.126 


.738 










Vi 


.840 


.546 


.147 


1.087 


.840 


.252 


.294 


1.714 


Vi 


1.050 


.742 


.154 


1.473 


1.050 


.434 


.308 


2.440 


1 


1.315 


.957 


.179 


2.171 


1.315 


.599 


.358 


3.659 


IM 


1.660 


1.278 


.191 


2.996 


1.660 


.896 


.382 


5.214 


IM 


1.900 


1.500 


.200 


3.631 


1.900 


1.100 


.400 


6.408 


2 


2.375 


1.939 


.218 


5.022 


2.375 


1.503 


.436 


9.029 


2^ 


2.875 


2.323 


.276 


7.661 


2.875 


1.771 


.552 


13.695 


3 


3.500 


2.900 


.300 


10.252 


3.500 


2.300 


.600 


18.583 


W2 


4.000 


3.364 


.318 


12.505 


4.000 


2.728 


.636 


22.850 


4 


4.500 


3.826 


.337 


14.983 


4.500 


3.152 


.674 


27.541 


Wi 


5.000 


4.290 


.355 


17.611 


5.000 


3.580 


.710 


32.530 


5 


5.563 


4.813 


.375 


20.778 


5.563 


4.063 


.750 


38.552 


6 


6.625 


5.761 


.432 


28.573 


6.625 


4.897 


.864 


53.160 


7 


7.625 


6.625 


.500 


38.048 


7.625 


5.875 


.875 


63.079 


8 


8.625 


7.625 


.500 


43.388 


8.625 


6.875 


.875 


72.424 


9 


9.625 


8.625 


.500 


48.728 










10 


10.750 


9.750 


.500 


54.735 










11 


11.750 


10.750 


.500 


60.075 










12 


12.750 


11.750 


.500 


65.415 










13 


14.000 


13.000 


.500 


72.091 










14 


15.000 


14.000 


.500 


77.431 










15 


16.000 


15.000 


.500 


82.771 











Table 28-5. 





1 




1 










Length of tube 




Diameter | 






Circumference 


Transverse area 


per square foot 


Nominal 






Nominal 
thickness 


Nearest 
no. 













f 


weight 
















external 


internal 


jPer 


External 


Internal 




B. Wire 
Gauge 


External 


Internal 


External 
Square 


Internal 
Square 


Metal 
Square 


surface 


surface 




Inches 


Inches 


Inches 




Inches 


Inches 


inches 


inches 


inches 


' Feet 


Feet 


Pounds 


IM 


1.560 


.095 


13 


5.498 


4.901 


2.405 


1.911 


.494 


2.182 


2.448 


1.679 


9 


1.810 


.095 


13 


6.283 


5.686 


3.142 


2.573 


.569 


1.909 


2.110 


1.932 


2M 


2.060 


.095 


13 


7.069 


6.472 


3.976 


3.333 


.643 


1.697 


1.854 


2.186 


W2 


2.282 


.109 


12 


7.854 


7.169 


4.909 


4.090 


.819 


1..527 


1.674 


2.783 


m 


2.532 


.109 


12 


8.639 


7.955 


5.940 


5.036 


.904 


1.388 


1.508 


3.074 


3 


2.782 


.109 


12 


9.425 


8.740 


7.069 


6.079 


.990 


1.273 


1.373 


3.365 


3M 


3.010 


.120 


11 


10.210 


9.456 


8.296 


7.116 


1.180 


1.175 


1.269 


4.011 


3M 


3.260 


.120 


11 


10.996 


10.242 


9.621 


8.347 


1.274 


1.091 


1.171 


4.331 


m 


3.510 


.120 


11 


11.781 


11.027 


11.045 


9.677 


1.368 


1.018 


1.088 


4.652 


4 


3.732 


.134 


10 


12.566 


11.724 


12.566 


10.939 


1.627 


.954 


1.023 


5.532 


iV2 


4.232 


.134 


10 


14.137 


13.295 


15.904 


14.066 


1.838 


.848 


.902 


6.248 


5 


4.704 


.148 


9 


15.708 


14.778 


19.635 


17.379 


2.256 


.763 


.812 


7.669 



* Crane Go. 



Table 28-6. Surface Factors for Pipes 





Factors for 


Factors for 




Factors for 


Factor for 




Factors for 


Factors for 


Size 


reducing lin- 


reducing sq. 


Size 


reducing lin- 


reducing sq. 


Size 


reducmg lin- 


reducing sq. 


of pipe 


eal ft. to 


ft. to 


of pipe 


eal ft. to 


ft. to 


of pipe 


eal ft. to 


ft. to 




sq. ft. 


lineal ft. 




sq. ft. 


lineal ft. 




sq. ft. 


lineal ft. 


H 


.27 


3.64 


3 


.92 


1.09 


7 


2.00 


.50 


1 


.33 


2.90 


W% 


1.05 


.96 


8 


2.23 


.44 


IM 


.43 


2.30 


4 


1.19 


.85 


9 


2.50 


.40 


iy2 


.50 


2.01 


4}^ 


1.31 


.76 


10 


2.85 


.36 


2 


.62 


1.61 


5 


1.61 


.63 


12 


3.33 


.30 


W2 


,75 


1.33 


6 


1.75 


..58 









317 



Table 28-7. Expansion of Wrought-Iron Pipe on the Application of Heat* 



pipe is'fitTed"^ Increase in length in inches per foot when heated to 


Deg. fahr. 160 180 200 212 220 228 240 274 


.0128 .0144 ,016 .017 .0176 .0182 .0192 0219 


32 .0102 .0118 .0134 .0144 .015 .0157 .0166 0194 


50 .0088 .0104 .012 .013 .0136 .0142 .01.52 0179 


70 .0072 .0088 .0104 .0114 .012 .0126 .0136 .0163 


Coefficient;— .0000067 per deg. fahr. * Holland Heating Manual 


Table 28-8. Heat Units Per Pound and Weight Per Cubic Foot of Water 


Between 32 Deg. Fahr. and 340 Deg. Fahr.f 


S 0) 


11 


P.O 

+. o 


V V 


11 


u 
P.O 






51 






Is 

+. o 


u 




no 
*. o 
J5 




11 


Co 

*- o 




O 


MO 

■J Id 


t£ 


s" 


•So 




i.^ 


■B 


|& 


K 




a- 


rt ^ 




EB, 




bflu 

•S2 


^•s 


kI 


&3 




K£ 


&g 


108 


a£ 


&3 


Htj 


KU. 


^3 


0) „ 
H-o 

184 


Kd. 


^3 


222 


J3 V 


&3 


32 


0.00 


62.42 


70 


38.06 


62,30 


75.95 


61.90 


146 


113.86 


61.27 


151,89 


60.49 


190.1 


59.58 


33 


1.01 


62.42 


71 


39,06 


62.30 


109 


76,94 


61.88 


147 


114,86 


61.25 


185 


1.52.89 


60,47 


223 


191.1 


59.55 


34 


2.01 


62.42 


72 


40,05 


62,29 


110 


77,94 


61.86 


148 


115.86 


61,24 


186 


153.89 


60,45 


224 


192.1 


59.53 


35 


3,02 


62.43 


73 


41.05 


62.28 


111 


78,94 


61,85 


149 


116,86 


61.22 


187 


154.90 


60.42 


225 


193.1 


59.50 


36 


4.03 


62.43 


74 


42,05 


62.27 


112 


79,93 


61,83 


150 


117,86 


61,20 


188 


155.90 


60.40 


226 


194.1 


59.48 


37 


5,04 


62.43 


75 


43.05 


62.26 


113 


80,93 


61,82 


151 


118,86 


61.18 


189 


156.90 


60 38 


227 


195.2 


,59.45 


38 


6,04 


62,43 


76 


44,04 


62,26 


114 


81,93 


61,80 


152 


119,86 


61,16 


190 


157,91 


60.36 


228 


196.2 


59.42 


39 


7.05 


62,43 


77 


45,04 


62,25 


115 


82.92 


61,79 


153 


120.86 


61 , 14 


191 


158,91 


60.33 


229 


197.2 


59.40 


40 


8.05 


62,43 


78 


46.04 


62.24 


116 


83,92 


61,77 


154 


121.86 


61,12 


192 


1.59,91 


60.31 


230 


198.2 


59.37 


41 


9.05 


62.43 


79 


47.04 


62,23 


117 


84,92 


61.75 


155 


122.86 


61.10 


193 


160,91 


60.29 


231 


199.2 


59.34 


42 


10,06 


62.43 


80 


48.03 


62,22 


118 


85,92 


61.74 


1.56 


123.86 


61,08 


194 


161.92 


60.27 


232 


200.2 


59.32 


43 


11,06 


62.43 


81 


49.03 


62,21 


119 


86.91 


61.72 


157 


124.86 


61,06 


195 


162.92 


60.24 


233 


201.2 


59.29 


44 


12.06 


62.43 


82 


50.03 


62.20 


120 


87.91 


61.71 


1,58 


125,86 


61 , 04 


196 


163.92 


60.22 


234 


202.2 


59.27 


45 


13.07 


62,42 


83 


51.02 


62,19 


121 


88,91 


61,69 


159 


126,86 


61.02 


197 


164.93 


60.19 


235 


203.2 


,59.24 


46 


14,07 


62,42 


84 


52.02 


62,18 


122 


89.91 


61,68 


160 


127.86 


61.00 


198 


165.93 


60.17 


236 


204.2 


.59.21 


47 


15.07 


62,42 


85 


53.02 


62,17 


123 


90,90 


61.66 


161 


128.86 


60.98 


199 


166.94 


60.15 


237 


205.3 


59.19 


48 


16,07 


62,42 


86 


54.01 


62.16 


124 


91,90 


61.65 


162 


129.86 


60,96 


200 


167.94 


60.12 


238 


206.3 


.59.16 


49 


17.08 


62,42 


87 


55,01 


62.15 


125 


92.90 


61.63 


163 


130,86 


60,94 


201 


168,94 


60.10 


239 


207.3 


59.14 


50 


18.08 


62.42 


88 


56,01 


62.14 


126 


93,90 


61.61 


164 


131,86 


60.92 


202 


169.95 


60.07 


240 


208.3 


59.11 


51 


19,08 


62.41 


89 


57.00 


62.13 


127 


94,89 


61.59 


165 


132,86 


60.90 


203 


170.95 


60.05 


241 


209.3 


59.08 


52 


20,08 


62.41 


90 


.58,00 


62,12 


128 


95.89 


61.58 


166 


133,86 


60,88 


204 


171,96 


60,02 


242 


210.3 


59.05 


53 


21,08 


62,41 


91 


59.00 


62.11 


129 


96,89 


61.56 


167 


134,86 


60.86 


205 


172.96 


60,00 


243 


211.4 


.59.03 


54 


22,08 


62,40 


92 


60,00 


62.09 


130 


97,89 


61.55 


168 


135,86 


60.84 


206 


173,97 


59,98 


244 


212.4 


59.00 


55 


23.08 


62.40 


93 


60,99 


62,08 


131 


98.89 


61.53 


169 


136.86 


60.82 


207 


174,97 


59,95 


245 


213.4 


58.97 


56 


24.08 


62., 39 


94 


61,99 


62.07 


1,32 


99.88 


61,, 52 


170 


137,87 


60.80 


208 


175,98 


59,93 


246 


214.4 


58.94 


57 


25,08 


62,39 


95 


62,99 


62,06 


133 


100.88 


61,50 


171 


138.87 


60.78 


209 


176,98 


59.90 


247 


215.4 


.58.91 


58 


26,08 


62.38 


96 


63,98 


62,05 


134 


101.88 


61,49 


172 


139.87 


60.76 


210 


177,99 


59.88 


248 


216.4 


58.89 


59 


27.08 


62,37 


97 


64.98 


62.04 


135 


102.88 


61.47 


173 


140.87 


60.73 


211 


178.99 


59.85 


249 


217.4 


58.86 


60 


28.08 


62,37 


98 


65.98 


62,03 


136 


103.88 


61.45 


174 


141.87 


60.71 


212 


180.00 


59.83 


250 


218.5 


58.83 


61 


29,08 


62,36 


99 


66,97 


62,02 


137 


104.87 


61.43 


175 


142.87 


60.69 


213 


181.0 


59.80 


260 


228.6 


58.55 


62 


30.08 


62,36 


100 


67,97 


62,00 


138 


105,87 


61.41 


176 


143.87 


60.67 


214 


182.0 


59.78 


270 


238.8 


58.26 


63 


31.07 


62,35 


101 


68,97 


61.99 


139 


106,87 


61.40 


177 


144.88 


60.65 


215 


183,0 


59.75 


280 


249.0 


57.96 


64 


32.07 


62,35 


102 


69.96 


61,98 


140 


107,87 


61.38 


178 


145.88 


60.62 


216 


184,0 


59.73 


290 


259.3 


57.65 


65 


33.07 


62. 34 


103 


70.96 


61,97 


141 


108,87 


61.36 


179 


146.88 


60.60 


217 


185,0 


59.70 


300 


269.6 


57.33 


66 


34.07 


62.33 


104 


71.96 


61,95 


142 


109,87 


61 . 34 


180 


147.88 


60.58 


218 


186.1 


59.68 :U(I 279.9! 


57.00 


67 


35.07 


62.33 


105 


72.95 


61.94 


143 


110,87 


61,33 


181 


148.88 


60.56 


219 


187.1 


59.65 


320 


290.2 


56.66 


68 


36.07 


62.32 


106 


73.95 


61.93 


144 


111.87 


51,31 


182 


149.89 


60.53 


220 


188.1 


59.63 


330 


J00.6 


56.30 


69 


37.06 


62.31 


107 


74.95 


61.91 


145 112.86 


51.29 


183 


150.89 


50.51 


221 


189.1 


59.60 


340 


Jll.O 


55.94 



i Steam, Babcock & Wilcox Co. 



318 



Table 28-9. Dimensions of Cast-Iron Screwed Fittings* 




"^ ^^4- 



h 





A 








A 






n 














A 




r' 




J 




s 




r 


- 


■<-A— {-A-*- 




<— 


A— 


~A- 





Size, inches 



1 . 

IM. 

13^. 

2 . 

2^. 

3 . 
3M. 

4 . 

434. 

5 . 

6 . 

7 . 

8 . 

9 . 
10 . 
12 . 



Standard 

A B 

Inches Inches 



lA 
Hi 

2M 

3,^ 
3,^ 

3M 

4iV 
4t^ 

6J4 

7^ 



13^ 

lA 
1 j- 

A 16 

1 ii 

1 1^ 

.*■ 16 
0_3_ 
- 16 

2H 

Ol3 
-16 

^16 

3i^ 

3J^ 

4}4 
4H 

>'l6 

6 



Extra heavy 
A B 

Inches Inches 



2 

2M 

2^ 

3 

3>i 

43^ 
4H 

53^ 
53^ 

63/8 

734 
83^ 

113/g 

133.i 



1?^ 
13^ 

m 

2H 

2V2 



3 

3i^ 

3M 

4 

4M 
4% 
53^ 



Standard and extra heavy 

C D E F 

Inches Inches Inches Inches 



2M 
3 

334 

434 

5J€ 

63€ 

7J^ 
83^ 
9M 

115^ 
11^ 

13iV 
15M 

leu 

20 ii 

20H 

241^ 



IJ^ 

2M 

2M 
334 
3M 

43^ 

63/8 
6K 

934 

934 

lOM 

1234 

13^ 
16M 
16^ 
19J^ 



215 
16 

33^ 
Wi 

3^ 
3% 
43^ 

4M 

534 

6A 

7H 



2A 

2^ 
2% 
2% 

33^ 
3^ 
3^ 
434 



Note — The above dimensions are subject to a slight variation 

Table 28-10. 45-Degree Offset Connections 



*Cr; 



iCo. 















__ 






Pipe 
size 


Centre 

to 
centre 

A 


Centre 

to 

face 

B 


Face to 

face of 

45's 

C 












i 


Offset 
D 
















fi 


\ 


W- 


/^ 






) 




1^ 
2 

23^ 
3 

33^ 
4 

434 
5 

6 

7 
8 


3^ 
33^ 
Wi 
SVs 

53^ 
6 

7ys 

8M 
10 


li% 

1^ 
1-4 

-16 

2?^ 
2J^ 
2M 
3,^ 

3i^ 

3^8 

43^ 


¥2 
¥2 
% 

% 

H 
% 

1 

1 
1 

1 


2M 
2H 


tl 










3^ 

3J^ 








m 


Pipe 
size 


Centre 

to 
centre 

A 


Centre 
to 

face 
B 


Face to 

face of 

45's 

C 


Offset 
D 


434 
43^ 
5A 

5il 

6A 

7f6 


¥2 

M 
■ 1 

134 


234 
23^ 

2M 
33^ 


y% 
1 
13^ 

lA 




141 
Iff 
ifi 

2-h 



NOTE: The Offset D is equal to the distance A -=- 1.414 



319 



Table 28-11. Rules for Standard Weight Flanged Fittings 

American 1915 Standard, 125-lb. working pressure 
Shell thickness in inches 



13L 



T->-U- 



s 



1 



X^ 



Size fitting, 


Shell 


Size fitting. 


Shell 


Size fitting, 


Shell 


inches 


thickness 


inches 


thickness 


inches 


thickness 


o 


7 

rs 


5 


Yi 


12 


Yi 


2J^ 


tV 


6 


9 


14 


if 


3 


Vi 


7 


^ 


15 


^ 


W2 


Yi 


8 


H 


16 


H 


4 


Yi 


9 


M 


18 


1 


4J^ 


Y2 


10 


13. 

16 


20 


. lA 



1. Standard reducing elbows carry same dimensions center-to-face as regular elbows 
of largest straight size. 

2. Standard tees, crosses and laterals, reducing on run only, carry same dimensions 
face-to-face as largest straight size. 

3. Where long-turn fittings are specified, it has reference only to elbows which are made 
in two center-to-face dimensions and to be known as elbows and long-turn elbows, 
the latter being used only when so specified. 

4. All standard weight fittings must be guaranteed for 125-lb. working pressure, and 
each must have mark cast on indicating maker and guaranteed working steam pressure. 

5. Standard weight fittings and flanges to be plain faced, and bolt holes to be 3^ in. 
larger in diameter than bolts ; bolt holes to straddle center lines. 

6. Size of all fittings scheduled indicates inside diameter of ports. 

7. Square head bolts with hexagonal nuts are generally recommended for use. 

8. Double-branch elbows, side-outlet elbows and side-outlet tees, whether straight or 
reducing, carry same dimensions center-to-face and face-to-face as regular tees and elbows. 

9. Bull-head tees or tees increasing on outlet, will have same center-to-face and face- 
to-face dimensions as a straight fitting of the size of the outlet. 

10. Tees, crosses and laterals 16-in. and smaller, reducing on the outlet, use the same 
dimensions as straight sizes of the larger port. {ConUnued on next page) 





15 Standard, ] 


Table 2 
25-lb. working 


8-12. Stand 
pressure 


ard Flanges and Bolts 








19 


Pipe 


Flange 


Bolts 


Bolt Holes 






-■•It 


k- 


























^ 






Size 
P 


Diam. 
D 


Thick- 
ness 
T 


No. 


Size 
Diam. 


Bolt 
circle 
B.C. 






m 




o 




Diam. 




8 


nY?. 


lYs 


8 


Y 


IWa 


Yh 








■^ — > 


r - '— 


— —. 








9 


15 


Wh 


12 


Ya 


13 K 


Yh 






















10 
12 


16 
19 




12 

12 


Yh 

Yh 


14M 
17 


1 














1 


Pipe 


Flange 


Bolts 


Bolt 


Boles 


14 


21 


Wi 


12 


1 


1834 


















114 


Size 


Diam. 




No. 


Size 




Size 


15 


2214 


Wh 


16 


1 


20 


Wh 


P 


D 


T 




Diam. 


B.C. 


Diam. 


16 


2-iY?. 


1t^ 


16 


1 


21 K 


Wh 
















18 


25 


Itv 


16 


l/s 


22Ya 


Wi 


1 


4 


T% 


4 


7 
T6 


3 


g 

16 


IH 


41/, 


y?. 


4 


Vs 


•AYh 


fk 


20 


27 y, 


14 


20 


Wh 


25 


Wa 


lY?. 


5 


fk 


4 


Y?. 


■iYn 


Yh 


22 


29 H 


i~i 


20 


IH 


27^4 


Wh 


2 


6 


Ys 


4 


Yh 


m 


Y4 


24 


32 


1/8 


20 


Wa 


29 K, 


Wh 
















26 


UY4 


2 


24 


Wa 


31^4 


Wh 


2y?. 


7 


H 


4 


Yh 


5Y?. 


H 
















3 


lY?. 


K 


4 


Yh 


6 


K 


28 


■i(>Y?. 


2A 


28 


Wa 


34 


Wh 


■iY?. 


»Y, 


H 


4 


Yh 


7 


Ya 


30 


■i8H 


•2.Yi 


28 


Wh 


36 


W?. 


4 


9 


lA 


8 


Yh 


TY?. 


% 


32 


'HYa. 


2K 


28 


W?. 


■iSY?. 


Wh 
















34 


i-iH 


2A 


32 


W?. 


40 i4 


Wh 


4H 


9Y4 


s 


8 


Ya 


r% 


Yh 
















5 


10 


5 


8 


Y4 


»Y2 


Yh 


36 


46 


2^ 


32 


W?. 


42^4 


Wh 


6 


11 


1 


8 


H 


9Y?, 


Yh 


38 


48^4 


Wi 


32 


Wh 


4514 


Wa 


7 


12^2 


llV 


8 


H 


lOYi 


Ys 


40 


5054 


2Y2 


36 


Ws 


47K 


Wi 



320 



Sizes 18-in. and laiger, reducing on the outlet, are made in two lengths, depending on 
the size of the outlet, as given in the table of dimensions. 

11. For fittings reducing on the run only, a long-body pattern will be used. Y's are 
special and made to suit connections. Double-branch elbows are not made reducing on 
the run. 

12. Steel flanges, fittings and valves are recommended for superheated steam. 

13. If flanged fittings for lower working pressure than 125 lb. are made, they shall 
conform in all dimensions, except thickness of shell, to this standard and shall have the 
guaranteed working pressure cast on each fitting. Flanges for these fittings must be stand- 
ard dimensions. 



Table 28-13. Standard Flanged Reducing Laterals 
1915 Standard, 125-lb. Working Pressure 



, 


.1 1 


1 1 


- 


5 










-T 


1 


\ll 




lu_ 


_1LJ/ 






u 


H 


-< 





1, 1 / 



Reducing lateral 



Reducing-on-run 
lateral 



Reducing-on-run and 
branch lateral 



Run-R 



Size 



Dimensions, inches 

M N 



Flanges 
Diam. Thickness 



1 


— 


— 


— 


— 


— 


4 


A 


IM 


V-A or less 


8 


61^ 


\% 


6K 


414 


A. 


W2 


W2 " " 


9 


7 


9 


7 


5 


^ 


2 


2 " " 


lOJ^ 


8 


2H 


8 


6 


'A 


2J^ 


21^ " " 


12 


9J4 


2K 


93^ 


7 


a 


3 


3 " " 


13 


10 


3 


10 


^'A 


M 


3J^ 


3^ " " 


14M 


11>^ 


3 


11 K2 


834 


Hi 


4 


4 " " 


15 


12 


3 


12 


9 


a 


4^ 


Wi " " 


15}^ 


\W2 


3 


123^ 


9H 


15. 


5 


5 " " 


17 


13^ 


33^ 


13^ 


10 


15 

T6 


6 


6 " " 


18 


14J^ 


3J^ 


14^ 


11 


1 


7 


7 " " 


201^ 


\W2 


4 


16H 


12 3^^ 


ll^ 


8 


8 " " 


22 


viVi 


4>i 


171/2 


1334 


134 


9 


9 " " 


24 


i9y2 


4}^ 


1934 


15 


1^ 


10 


10 " " 


25}^ 


203^ 


5 


2034 


16 


1^ 


12 


12 " " 


30 


24>^ 


Wi 


24J4 


19 


IM 


14 


14 " " 


33 


27 


6 


27 


21 


Ws 


15 


15 " " 


34H 


28J^ 


6 


28 >4 


223^ 


154 


16 


16 " " 


36^ 


30 


(^Vi 


30 


2334 


lA 


18 


9 " " 


26 


25 


1 


2734 


25 


1,^ 


18 


18 to 10 inc. 


39 


32 


7 


32 


25 


l^ 


20 


10 and less 


28 


27 


1 


2934 


273^ 


Hi 


20 


20 to 12 inc. 


43 


35 


8 


35 


27y2 


Hi 


22 


10 and less 


29 


283^ 


Vi 


31}/2 


29 J^ 


m 


22 


22 to 12 inc. 


46 


3714 


SV2 


37^2 


29^ 


Hi 


24 


12 and less 


32 


si'A 


V2 


34^ 


32 


VA 


24 


24 to 14 inc. 


49M 


m/i 


9 


4034 


32 


iVs 


26 


12 and less 


35 


35 





38 


3434 


2 


26 


26 to 14 inc. 


53 


44 


9 


44 


343^ 


2 


28 


14 and less 


37 


37 





40 


36 H 


2^ 


28 


28 to 15 inc. 


56 


46^ 


9H 


46^ 


3634 


2^ 


30 


15 and less 


39 


39 





42 


3«M 


2% 


30 


30 to 16 inc. 


59 


49 


10 


49 


38 34 


2ys 



321 



Table 28-14. Standard Flanged Bull-Head Reducing Tees and Crosses 
1915 Standard, 125-lb. Working Pressure 






Reducing tee 



h^^=1 



^r^rrli i L'^^ 



\l-z: 



Reducing cross 



^ 



— A >j< A > 



£ 



Reducing- on-run tee 



^citi 



Bull-head tee 



->|< — J > 



mr 



rrm - 

Reducing-on-run and 
Branch tee cross 



"T 

cr- 



c:^^^ 



^ 



FP- 



Reducing-on-run branch 



Size 



Branch b 



A & J 



Dimensions, inches 



Flanges 
Diam. Thickness 



1 


- 


— 




— 


— 








4 


1^ 


IM 


1 or less 


3M 


3M 








4J^ 


¥2 


iy2 


IM 




" 


4 


4 








5 


^ 


2 


I'A 






I'A 


4}^ 








6 


H 


2^ 


2 




" 


5 


5 








7 


H 


3 


2M 




" 


5^ 


5M 


Note — A reduction in 


size on 


7M 


H 


3J^ 


3 




" 


6 


6 


the run does 


not affect the 


8M 


13 


4 


3J^ 




" ■ 


6H 


6>i 


dimensions but branch out- 


9 


iS. 














lets of small size such 


as are 






4,14 


4 




" 


7 


7 


• listed below will reduce the 


9li 


T* 


5 


4M 




'* 


■7V2 


7J^ 


dimensions of 


fittings 


18 in. 


10 


a 


6 


5 




** 


8 


8 


or over in size 






11 


1 


7 


6 




" 


8M 


8M 








12 "4 


1,^ 


8 


7 




" 


9 


9 








13M 


IVb 


9 


8 




'* 


10 


10 








15 


IVs 


10 


9 




" 


11 


11 








16 


1t% 


12 


10 




" 


12 


12 








19 


m 


14 


12 




" 


14 


11 








21 


Ws 


15 


14 
15 




" 


14>^ 
15 


15 


Branch b 


J 


K 


22 K 
23J^ 


Wi 


16 








ll^ 


18 


18 to 


14 


inc. 


16>^ 


16K 


12 or less 


13 


15V^ 


25 


1 9 
1t6 


20 


20 to 


15 


inc. 


18 


18 


14 " " 


14 


17 


271^ 


1 11 

J- 16 


22 


22 to 


16 


inc. 


20 


20 


15 " " 


14 


18 


29}^ 


IH 


24 


24 to 


18 


inc. 


■22 


22 


16 " " 


15 


19 


32 


Wi 


26 


26 to 


20 


inc. 


23 


23 


18 " " 


16 


20 


34M 


2 


28 


28 to 


20 


inc. 


24 


24 


18 " " 


16 


21 


3614 


2t^ 


30 


30 to 


22 


inc. 


25 


25 


20 " " 


18 


23 


38M 


2}^ 


32 


32 to 


22 


inc. 


26 


26 


20 " " 


18 


24 


41 M 


m 


34 


34 to 


24 


inc. 


27 


27 


22 " " 


19 


25 


43M 


2^ 


36 


36 to 


26 


inc. 


28 


28 


24 " " 


20 


26 


46 


2^8 


38 


38 to 


26 


inc. 


29 


29 


24 " " 


20 


28 


48M 


^% 


40 


40 to 


28 


inc. 


30 


30 


26 " " 


22 


29 


50M 


2^ 



322 



Table 28-15. Standard Flanged Elbows, Crosses, Laterals and Reducers 
1915 Standard, 125-lb. Working Pressure 





Long-turn elbow 



Reducing elbow 



Double-branch 
elbow 



_□! 



Straight tee 



T^P" 



J" 



Straight cross 




Straight lateral 



l< G- 



Reducer 



Size 
Run-R 



Dimensions, inches 
C D 



Flange 
Biam. Thickness 



1 


33^ 


5 


IM 


I'A 


5M 


— 


4 


7 
T6 


IM 


m 


^Vo 


2 


8 


63€ 


— ■ 


434 


J4 


I'A 


4 


6 


23i 


9 


i 


— 


5 


ffe 


2 


4H 


6,^ 


23^ 


103-^ 


8 


— 


6 


^ 


23^ 


5 


7 


3 


12 


934 


— . 


7 


. H 


3 


5J^ 


7% 


3 


13 


10 


6 


734 


M 


iy2 


6 


8J^ 


33^ 


14^ 


1134 


63^ 


834 


il 


4 


6y2 


9 


4 


15 


12 


7 


9 


H 


4}^ 


7 


93^ 


4 


1534 


1234 


734 


934 


il 


5 


7V2 


lOK 


43^ 


17 


1334 


8 


10 


15 


6 


8 


IIM 


5 


18 


1434 


9 


11 


1 


7 


8M 


12M 


53^ 


203^ 


16H 


10 


1234 


ll^ 


8 


9 


14 


5^ 


22 


173^ 


11 


1334 


Wi 


9 


10 


isu 


6 


24 


1934 


ll"^ 


15 


IVs 


10 


11 


\6V2 


63^ 


2534 


2034 


12 


16 


l^ 


12 


12 


19 


73^ 


30 


24M 


14 


19 


IK 


14 


14 


21H 


73-^ 


33 


27 


16 


21 


IVs 


15 


14H 


22M 


8 


343^ 


2834 


17 


22M 


m 


16 


15 


24 


8 


3634 


30 


18 


2334 


lA 


18 


16H 


261^ 


83^ 


39 


32 


19 


25 


1^ 


20 


18 


29 


934 


43 


35 


20 


2734 


Hi 


22 


20 


313^ 


10 


46 


373^ 


22 


2934 


Hi 


24 


22 . 


34 


11 


4934 


4034 


24 


32 


V/s 


26 


23 


363^ 


13 


53 


44 


26 


3434 


2 


28 


24 


39 


14 


56 


46 


28 


3634 


2A 


30 


25 


413^ 


15 


59 


49 


30 


38M 


234 


32 


26 


44 


16 


— 


— 


32 


41 M 


23€ 


34 


27 


463'2 


17 


— 


— 


34 


43 M 


2A 


36 


28 


49 


18 








36 


46 


254 


38 


29 


513^ 


19 


— 


— 


38 


48^ 


ZVs 


40 


30 


54 


20 


— 




40 


50M 


2^ 



323 



Table 28-16. Rules for Extra-Heavy Flanged Fittings 

American 1915 Standard 250-lb. Working Pressure 
Shell thickness in inches 






Size fitting, 


Shell 


Size fitting, 


Shell 


Size fitting. 


Shell 




inches 


thickness 


inches 


thickness 


inches 


thickness 




2 


Vs 


5 


% 


12 


w% 


"i 


2J^ 


Vi 


6 


13. 


14 


lA 


-1) 


3 


Ys 


7 


% 


15 


^Vx 




3}^ 


Vs 


8 


15 
T6 


16 


lA 




4 


% 


9 


1 


18 


1=^ 




41^ 


16 


10 


li^ 


20 


1^ 



1. Extra heavy reducing elbows carry same dimensions center-to-face as regular elbows 
of Itirgest straight size. 

2. Extra heavy tees, crosses and laterals, reducing on run only, carry same dimensions 
face-to-face as largest straight size. 

3. Where long-turn fittings are specified, it has reference only to elbows which are made 
in two center-to-face dimensions and to be known as elbows and long-turn elbows, the latter 
being used only when so specified. 

4. Extra heavy fittings must be guaranteed for 250-lb. working pressure, and each 
fitting must have some mark cast on it indicating the maker and guaranteed working steam 
pressure. 

5. All extra heavy fittings and flanges to have a raised surface i^ in. high inside of bolt 
holes for gaskets. Thickness of flanges and center-to-face dimensions of fittings include this 
raised surface. Bolt holes to be Y^ in. larger in diameter than bolts. Bolt holes to straddle 
center lines. {Continued on next page.) 



Table 28-17. Extra-Heavy Pipe Flanges and Bolts 

1915 Standard, 250-lb. Working Pressure 











-A^ 








Pipe 

Size 


Flange 


Bolts 


Bolt holes 




/y^ 


§^ i " 


Diam. 


Thick- 






Bolt 








^k 




} 






P 


D 


ness 
T 


No. 


Size 


circle 
B. C. 


hole 






^^ 


8 


15 


15/^ 


12 


K 


13 






r 


















9 


\6H 


1% 


12 


1 


14 


\v^ 












10 
12 

14 


20,1^ 
23 


1^8 

2 

2H 


16 
16 

20 


1 
1.1 8 


I^Va 
17M 

20M 


IM 


Pipe 


Flange 


Bolts 


Bolt 


holes 
















Wa 


Siie 


Diam. 


Thick- 


No. 


Size 


Bolt 


Bolt 
hole 


15 


241^ 


2^ 


20 


IH 


21 J^ 


w^ 


P 


D 


T 






B.C. 


16 


2b/, 


2K 


20 


IH 


22/, 


IH 
















18 


28/, 


2V, 


24 


lyA 


24^4 


l^s 
















1 


4K« 


H 


4 


y?. 


3K 


Vs 
















I'/i 


5 


H 


4 


y?. 


ZH 


% 


20 


30 ^ 


2y?, 


24 


IH 


27 


\y-? 


IH 


6 


i3. 


4 


y« 


4,1/, 


Va 


22 


33 


2yH 


24 


ly?, 


2914 


1^/8 


2 


(>y?. 


Vh 


4 


'A 


5 


Va 


24 


36 


2^4 


24 


IVh 


32 


VYa 
















26 


3814 


2H 


28 


m 


34/, 


IYa 


•2yo, 


-iy?. 


1 


4 


% 


SVh 


Vs 
















3 


m 


IH 


8 


■% 


6V8 


14 


28 


40^4 


21* 


28 


i-% 


37 


m 


■sy?. 


y 


Ifk 


8 


H 


7i4 


% 


30 


43 


3 


28 


VH 


39^4 


1% 


4 


10 


li4 


8 


■% 


r/n 


% 


32 


45 '4 


■m 


28 


\% 


^\y■?. 


2 
















34 


47/, 


3K 


28 


i% 


43/, 


2 


'iV?. 


tOH: 


lA 


8 


Va 


8'/s 


Vs 
















5 


11 


Ws 


8 


Va 


9^4 


Vs 


36 


50 


3^, 


32 


IVh 


46 


2 


6 


i2y?. 


1t^ 


12 


Va 


loys 


Vb 


38 


5214 


3,^ 


32 


IV, 


48 


2 


7 


14 


1^2 


12 


% 


liK 


1 


40 


54}^ 


3t% 


36 


\y% 


5014 


2 



324 



6. Size of all fittings scheduled indicates inside diameter of ports. 

7. Square head bolts with hexagonal nuts are generally recommended for use. 

8. Double branch elbows, side outlet elbows and side outlet tees, whether straight or 
reducing sizes, carry same dimensions center-to-face and face-to-face as regular tees and 
elbows. 

9. Bull-head tees or tees increasing on outlet, will have same center-to-face and face-to- 
face dimensions as a straight fitting of the size of the outlet. 

10. Tees, crosses and laterals 16-in. and smaller, reducing on the outlet, use the same 
dimensions as straight size of the larger port. Sizes 18 in. and larger, reducing on the outlet, 
are made in two lengths, depending on the size of the outlet as given in the table of dimen- 
sions. 

11. For fittings reducing on the run only a long body pattern will be used. Y's are 
special and made to suit connections. Double branch elbows are not made reducing on the 
run. 

12. Steel flanges, fittings and valves are recommended for superheated steam. 






Table 28-18. Extra-Heavy Flanged Reducing Laterals 

1915 Standard, 250-lb. Working Pressure 




Reducing lateral 




Reducing-on-run 
lateral 




Reducing on-run and 
Branch lateral 



Size 



Branch b 



Dimensions, inches 
M 



Flanges 
Diam. Thickness 



1 


— 


— 











4>i 


11 


IH 


\\i and less 


Wz 


■7M 


2}^ 


iVi 


5 


Vi 


W2 


W2 " " 


11 


83^ 


W2 


SV2 


6 


H 


2 


O ft It 


11?^ 


9 


2y2 


9 


6H 


% 


2^ 


2K " " 


13 


10}^ 


Wi 


10V2 


7y2 


1 


3 


3 " " 


14 


11 


3 


11 


8H 


Wi 


3J^ 


3M " " 


15}^ 


123^ 


3 


12)^ 


9 


lA 


4 


4 " " 


16H 


133^ 


3 


13}^ 


10 


IM 


41^ 


41^ " " 


18 


14)^ 


Wi 


14>^ 


10^ 


lA 


5 


5 " " 


18M 


15 


W2 


15 


11 


Ws 


6 


6 " " 


21 J^ 


yiVi 


4 


17}^ 


12J^ 


\ii 


7 


7 " " 


23J^ 


19 


m 


19 


14 


iy2 


8 


8 " ■' 


25 J^ 


20^ 


5 


201^ 


15 


1% 


9 


9 " ■' 


27>^ 


22K 


5 


22 J^ 


16J4 


m 


10 


10 " " 


29}^ 


24 


5K 


24 


17^ 


m 


12 


12 " " 


33J^ 


27 J^ 


6 


2iy2 


20^ 


2 


14 


14 " " 


373^ 


31 


6H 


31 


23 


2H 


15 


15 " '■ 


39>^ 


33 


(^Vi 


33 


24>^ 


2A 


16 


16 " •' 


42 


34^ 


iy2 


341^ 


25}^ 


2K 


18 


9 •' " 


34 


31 


3 


32y2 


28 


2^ 


18 


16 to 10 inc. 


45>^ 


37J^ 


8 


37M 


28 


2ys 


20 


10 and less 


37 


34 


3 


36 


3oy2 


2y2 


20 


18 to 12 inc. 


49 


401^' 


&y2 


401^ 


30}4 


2M 


22 


10 and less 


40 


37 


3 


39 


33 


2J^ 


22 


20 to 12 inc. 


53 


433^ 


W2 


43 J^ 


33 


2^ 


24 


12 and less 


44 


41 


3 


43 


36 


2H 


24 


22 to 14 inc. 


57'^ 


47^ 


10 


47M 


36 


2M 



325 



Table 28-19. Extra-Heavy Flanged Bull-Head Reducing Tees and Crosses 
1915 Standard, 250-lb. Working Pressure 



k — ^J — >|' 



II 



._i- 



\<'b->\ 
Reducing tee 



<— J — »l<— J — . 




n 1 I ! r 

1 

fill 


T,. 
1. 



\<-b>\ 
Reducing cross 



4 



'A 



Reducing- on- run tee 



--T 'JZ 



Bull-head tee 



i±± 



5-1- 



Reducing-on-run and branch tee 



■J ><— J — >■ 



I I I I 



I I I I ^ 

Reducing-on-run and branch cross 



Run-R 



Size 



Branch b 



Dimensions, inches 
K 



Flanges 
Diam. Thickness 



1 


— 


— 


— 








44 


fi 


IM 


1 or less 


4M 


414 








5 


H 


iy2 


IK " " 


4M 


4}-^ 








6 


H 


2 


IK " " 


5 


5 








6y2 . 


Vs 


2y2 


2 " " 


5H 


5,4 








7J^ 


1 


3 


2K " " 


6 


6 








SH 


1}^ 


3J^ 


3 " " 


6J^ 


6,'i 








9 


lA 


4 


iVz " " 


7 


1 


Note — A reduction in 


size on 


10 


IH 










the run does 


not alTect the 






4J^ 


4 " " 


7>i 


^'A 


dimensions but branch out- 


104 


l^ 


5 


m " " 


8 


8 


lets of smaller 


size than those 


11 


Wi 


6 


5 " " 


SV2 


S14 


listed below will reduce the 


12,4 


li^ 


7 


6 " " 


9 


9 


dimensions of 
or over in size 


fittings 


18 in. 


14 


14 


8 


7 " " 


10 


10 








15 


1^ 


9 


8 " " 


10>4 


10 14 








16}^ 


IM 


10 


9 " " 


iVA 


113-^ 








174 


VA 


12 


10 " " 


13 


13 








204 


2 


14 


12 " " 


15 


15 








23 


24 


15 


14 " " 


153^ 


15 H 


B anch 


J 


K 


244 


2A 


16 


15 " " 


163^ 


16M 






254 


2J4 


18 


18 to 14 inc. 


18 


18 


12 or less 


14 


17 


28 


2?^ 


20 


20 to 15 inc. 


19J^ 


194 


14 " " 


■154 


18,4 


304 


24 


22 


22 to 16 inc. 


20M 


204 


15 " " 


164 


20 


33 


254 


24 


24 to 18 inc. 


22y2 


224 


16 " " 


17 


21,4 


36 


2M 


26 


26 to 20 inc. 


24 


24 


18 " " 


19 


23 


38M 


2H 


28 


28 to 20 inc. 


26 


26 


18 " " 


19 


24 


403^ 


21i 


30 


30 to 22 inc. 


27}^ 


274 


20 " " 


204 


254 


43 


3 


32 


32 to 22 inc. 


29 


29 


20 " " 


204 


264 


45 J4 


34 


34 


34 to 24 inc. 


30,14 


30 K 


.^.^ ti «t 


22 


28 


474 


34 


36 


36 to 26 inc. 


32M 


324 


24 " " 


234 


294 


50 


354 


38 


38 to 26 inc. 


34 


34 


24 " " 


234 


304 


.52 K 


3i% 


40 


40 to 28 inc. 


35, ^ 


354 


26 " " 


25 


314 


544 


35^ 



326 



Table 28-20. Extra-Heavy Flanged Elbows, Crosses, Laterals and Reducers 

1915 Standard, 250-Ib. Working Pressure 




Double-branch 
elbow 



-( i I J I 
Straight tee 



Straight cross 




Straight lateral 



If 
cr- 



Size 
Run-R 



Dimensions, inches 
C D 



Flange 
Diam. Thickness 



1 


4 


5 


2 


S'A 


6A 


— 


43^ 


H 


IM 


4M 


5^ 


23^ 


9A 


■^H 


— 


5 


% 


IJ^ 


4^ 


6 


2M 


11 


&A 


— 


6 


*t 


2 


5 


6J^ 


3 


iiA 


9 


— 


63^ 


Vs 


2^ 


5J^ 


7 


W2 


13 


lOH 





73^ 


1 


3 


6 


7H 


S'A 


14 


11 


6 


834 


\v% 


sy2 


6V2 


8^ 


4 


15}-^ 


121^ 


6 14 


9 


lA 


4 


7 


9 


4>^ 


163^ 


133^ 


7 


10 


IM 


m 


I'A 


9^ 


43^ 


18 


14 U 


73^ 


103^ 


lA 


5 


8 


lOK 


5 


WA 


15 


8 


11 


1^8 


6 


SV2 


n'A 


53i 


21H 


nji 


9 


1234 


1t^ 


7 . 


9 


12H 


6 


23}^ 


19 


10 


14 


13-2 


8 


10 


14 


6 


25}^ 


203^ 


11 


15 


VA 


9 


10}^ 


15M 


6}^ 


27}^ 


2234 


113^ 


163i 


IH 


10 


11^ 


161^ 


7 


291^ 


24 


12 


173^ 


VA 


12 


13 


19 


8 


33}^ 


273^ 


14 


203^ 


2 


14 


15 


2iy2 


83^ 


373^ 


31 


16 


23 


2^ 


15 


15}^ 


22M 


9 


3914 


33 


17 


243^ 


2^ 


16 


16>^ 


24 


9;^ 


42 


343^ 


18 


251.^ 


234 


18 


18 


26M 


10 


45}^ 


373^ 


19 


28 


25/8 


20 


19H 


29 


IOI2 


49 


403^ 


20 


303^ 


23^ 


22 


20J^ 


31^ 


11 


53 


433^ 


22 


33 


2% 


24 


22 J^ 


34 


12 


57 H 


4734 


24 


36 


2M 


26 


24 


36M 


13 






26 


3834 


2H 


28 


26 


39 


14 








28 


40M 


2if 


30 


27^ 


4114 


15 


— 


— 


30 


43 


3 


32 


29 


44 


16 


— 


_ 


32 


4534 


33^ 


34 


30K 


46H 


17 


— 


— 


34 


473-^ 


334 


36 


321^ 


49 


18 








36 


50 


5% 


38 


34 


51 J^ 


19 


— 


— 


38 


52 3i 


3A 


40 


35H 


54 


20 


— 


— 


40 


543^ 


3^ 



■327 



Table 28-21. Properties of Saturated Steam 

Reproduced by permission from Marks and Davis Steam Tables and Diagrams. Copyright, 1909, by 

Longmans, Green & Co. 



Pressure, lb. 
absolute 



Temperature, 
deg. fahr. 



Specific volume, 
cu. ft. per lb. 



Heat of the 
liquid, B.t.u. 



Latent heat of 
evap., B.t.u, 



Total heat of 
steam, B.t.u. 



Pressure, lb. 

absolute 



1 


101.83 


333.0 


69.8 


1034.6 


1104.4 


1 


o 


126.15 


173.5 


94.0 


1021.0 


1115.0 


2 


3 


141.52 


118.5 


109.4 


1012.3 


1121.6 


3 


4 


153.01 


90.5 


120.9 


1005.7 


1126.5 


4 


5 


162.28 


73.33 


130.1 


1000.3 


1130.5 


5 


6 


170.06 


61.89 


137.9 


995.8 


1133.7 


6 


7 


176.85 


53.56 


144.7 


991.8 


1136.5 


7 


8 


182.86 


47.27 


150.8 


988.2 


1139.0 


8 


9 


188.27 


42.36 


156.2 


985.0 


1141.1 


9 


10 


193.22 


38.38 


161.1 


982.0 


1143.1 


10 


11 


197.75 


35.10 


165.7 


979.2 


1144.9 


11 


12 


201.96 


32.36 


169.9 


976.6 


1146.5 


12 


13 


205.87 


30.03 


173.8 


974.2 


1148.0 


13 


14 


209.55 


28.02 


177.5 


971.9 


1149.4 


14 


14.7 


212.0 


26 79 


180 


970.4 


1150.4 


14.7 


15 


213.0 


26.27 


181.0 


969.7 


1150.7 


15 


16 


216.3 


24.79 


184.4 


967.6 


1152.0 


16 


17 


219.4 


23.38 


187.5 


965.6 


1153.1 


17 


18 


222.4 


22.16 


190.5 


963.7 


1154.2 


18 


19 


225.2 


21.07 


193.4 


961.8 


1155.2 


19 


20 


228.0 


20.08 


196.1 


960.0 


1156.2 


20 


22 


233.1 


18.37 


201.3 


956.7 


11.58.0 


22 


24 


237.8 


16.93 


206.1 


953.5 


1159.6 


24 


26 


242.2 


15.72 


210.6 


950.6 


1161.2 


26 


28 


246.4 


14. 67 


214.8 


947.8 


1162.6 


28 


30 


250.3 


13.74 


218.8 


945.1 


1163.9 


30 


32 


254.1 


12.93 


222.6 


942.5 


1165.1 


32 


34 


257.6 


1*^ 22 


226.2 


940.1 


1166.3 


34 


36 


261.0 


11.58 


229.6 


937.7 


1167.3 


36 


38 


264.2 


11.01 


232.9 


935.5 


1168.4 


38 


40 


267.3 


10.49 


236.1 


933.3 


1169.4 


40 


42 


270.2 


10.02 


239.1 


931.2 


1170.3 


42 


44 


273.1 


9.59 


242.0 


929.2 


1171.2 


44 


46 


275.8 


9.20 


244.8 


927.2 


1172.0 


46 


48 


278.5 


8.84 


247.5 


925.3 


1172.8 


48 


50 


281.0 


8.51 


250.1 


923.5 


1173.6 


50 


52 


283.5 


8.20 


252.6 


921.7 


1174.3 


52 ■ 


54 


285.9 


7.91 


255.1 


919.9 


1175.0 


54 


56 


288.2 


7.65 


257.5 


918.2 


1175.7 


56 


58 


290.5 


7.40 


259.8 


916.5 


1176.4 


58 


60 


292.7 


7.17 


262.1 


914.9 


1177.0 


60 


62 


294.9 


6.95 


264.3 


913.3 


1177.6 


62 


64 


297.0 


6.75 


266.4 


911.8 


1178.2 


64 


66 


299.0 


6.56 • 


268.5 


910.2 


1178.8 


66 


68 


301.0 


6.38 


270.6 


908.7 


1179.3 


68 


70 


302.9 


6.20 


272.6 


907.2 


1179.8 


70 


72 


304.8 


6.04 


274.5 


905.8 


1180.4 


72 


74 


306.7 


5.89 


276.5 


904.4 


1180.9 


74 


76 


308.5 


5.74 


278.3 


903.0 


1181.4 


76 


78 


310.3 


5.60 


280.2 


901.7 


1181.8 


78 


80 


312.0 


5.47 


282.0 


900.3 


1182.3 


80 



328 





Table 28 


-21. Properties of Saturated Steam — Continued 




Pressure, lb. 

absolute 


Temperature, 
deg. fahr. 


Specific volume, 
cu. ft. per lb. 


Heat of the 
liquid, b.t.u. 


Latent heat of 
evap., b.t.u. 


Total heat of 
steam, b.t.u. 


Pressure, lb. 
absolute 


82 
84 
86 
88 


313,8 
315.4 
317.1 
318.7 


5.34 
5.22 
5.10 
5.00 


283.8 
285.5 
287.2 
288.9 


899.0 
897.7 
896.4 
895.2 


1182.8 
1183.2 
1183.6 
1184.0 


82 
84 
86 
88 


90 
92 
94 
96 


320.3 
321.8 
323.4 
324.9 


4.89 
4.79 
4.69 
4.60 


290.5 
292.1 
293.7 
295.3 


893.9 
892.7 
891.5 
890.3 


1184.4 
1184.8 
1185.2 
1185.6 


90 
92 
94 
96 


98 
100 
105 
110 


326.4 
327.8 
331.4 
334.8 


4.51 
4.429 
4.230 
4.047 


296.8 
298.3 
302.0 
305.5 


889.2 
888.0 
885.2 
882.5 


1186,0 
1186.3 
1187.2 
1188.0 


98 
100 
105 
110 


115 
120 
125 
130 


338.1 
341.3 
344.4 
347.4 


3.880 
3.726 
3.583 
3.452 


309.0 
312.3 
315.5 
318.6 


879.8 

877.2 
874.7 
872.3 


1188.8 
1189.6 
1190.3 
1191.0 


115 
120 
125 
130 


135 
140 
145 
150 


350.3 
353.1 
355.8 
358.5 


3.331 
3.219 
3.112 
3.012 


321.7 
324.6 
327.4 
330.2 


869.9 
867.6 
865.4 
863.2 


1191.6 
1192.2 
1192.8 
1193.4 


135 
140 
145 
150 


155 
160 
165 
170 


361.0 
363.6 
366.0 
368.5 


2 920 
2.834 
2.753 
2.675 


332.9 
335.6 
338.2 
340.7 


861.0 
858.8 
856.8 
854.7 


1194.0 
1194.5 
1195.0 
1195.4 


- 155 
160 
165 
170 


175 
180 
185 
190 


370.8 
373.1 
375.4 
377.6 


2.602 
2.533 
2.468 
2.406 


343.2 
345.6 
348.0 
350.4 


852.7 
850.8 
848.8 
846.9 


1195.9 
1196.4 
1196.8 
1197.3 


175 
180 
185 
190 


195 
200 
205 
210 


379.8 
381.9 
384.0 
386.0 


2.346 

2 290 
2.237 
2.187 


352.7 
354.9 
357.1 
359.2 


845.0 
843.2 
841.4 
839.6 


1197.7 
1198.1 
1198.5 
1198.8 


195 
200 
205 
210 


215 
220 
225 
230 


388.0 
389.9 
391.9 
393.8 


2.138 
2.091 
2.046 
2.004 


361.4 
363.4 
365.5 
367.5 


837.9 
836.2 
834.4 
832.8 


1199.2 
1199,6 
1199.9 
1200.2 


215 
220 

225 
230 


235 

240 
245 
250 


395.6 
397.4 
399.3 
401.1 


1.964 
1.924 
1.887 
1.850 


369.4 
371.4 
373.3 
375.2 


831.1 
829.5 
827.9 
826.3 


1200.6 
1200.9 
1201.2 
1201.5 


235 
240 
245 
250 



Table 28-22. Indicated Horsepower of an Engine 

A = area of the piston in square inches. P = niean efTeclive pressure of the steam on the piston, 
lb. per sq. in. L = length of stroke in ft. N=number of working strokes per min.= 2 X r. p. m. for 
double-acting cylinder. 

PLAN 

Then i.hp.= 

33,000 

The mean pressure in the cylinder of a non-condensing engine when cutting off at 

}4, stroke = boiler pressure multiplied by . 597 J^ stroke = boiler pressure multiplied by . 919 

^ " = " " " " .670 J^ " = " " " " .937 

3^ " = " " " " .743 3^ " = " " " " .966 

J^ " = " " " ■• .847 Va " = " " " " .992 

329 



Table 28-23. Dimensions of Horizontal Return Tubular Boilers"" 
Corresponding to Am. Soc. M. E. Standards 



Horse 
power 



34 
36 
39 
36 

30 
45 
42 
35 

52 
48 
40 

47 

45 
43 
55 
53 

50 
63 
60 
58 

85 
73 
68 
96 

82 

77 

111 

95 

83 
125 
106 

93 

136 
123 
107 
153 

138 
120 
169 
153 

134 
178 
167 
145 

197 
186 
161 



Heat- 
ing 
sur- 
face 

Sq. ft. 



SheU 



370 
430 
470 
430 

360 
540 
500 
420 

620 
570 
480 
560 

540 
510 
660 
630 

600 
750 
720 
700 

1021 
872 
822 

1147 

980 
924 

1338 

113 

993 
1504 
1272 
1116 

1632 
1474 
1289 
1834 

1657 
1448 
2037 
1839 

1608 
2139 
2001 
1745 

2375 
2232 
1938 



Dia. 
In. 

42 

42 
48 
48 

48 
48 
48 
48 

48 
48 
48 
54 

54 
54 
54 
54 

54 
54 
54 
54 

60 
60 
60 
60 

60 
60 
66 
66 

66 
66 
66 
66 



Lgth 
Feet 



12 
14 
12 
12 

12 
14 
14 
14 

16 
16 
16 
12 

12 
12 
14 
14 

14 
16 
16 
16 

16 
16 
16 
18 

18 
18 
16 
16 

16 
18 
18 
18 

16 
16 
16 
18 

18 
18 
20 
20 

20 
18 
18 
18 



78 20 
78 20 
78 20 



THICKNESS OF SHELLS AND HEADS 



Tubes 



No. 

X 

34 
34 
44 
34 

24 
44 
34 
24 

44 
34 
24 
54 

44 
36 
54 

44 

36 
54 
44 
36 

76 
54 

44 
76 

54 

44 

102 

72 

54 
102 

72 
54 

126 
96 

72 
126 

96 

72 

126 

96 



148 
118 



148 

118 

88 



Dia. 
In. 



3 

3 
3 

4 
3 

Wi 

4 

3 

3J4 

4 

3 

3}-; 

4 
3 

3V'2 

4 

3 

33-2 

4 

3 

S}4 

4 

3 

3}4 
4 
3 
3^2 

4 
3 

3>^ 
4 

3 

3}'> 

4 

3 

4 
3 

4 
3 

4 

3 

■i'A 

4 



Lgth 
Feet 



12S-Lb. 
working pressure 



Shell Heads 
In. In. 



12 , ,. 

u a 

14 
14 

16 
16 
16 
12 



12 
12 
14 
14 

14 
16 
16 
16 

16 
16 
16 
18 

18 
18 
16 
16 

16 
18 
18 
18 

16 
16 
16 
18 

18 
18 
20 
20 

20 
18 
18 
18 

20 
20 
20 



5yi 



Vb 



y% 
% 

Yb 
Vb 



Yb 



Long 
joint 



SheU 
In. 



150-Lb. 
working pressure 



Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 



Double Butt, 
Double Butt. 
Double Butt. 
Double Butt. 

Double Butt. 
Double Butt. 
Double Butt. 
Double Butt. 

Double Butt. 

Double Butt 

Double Butt 

Triple Butt. 

Triple Butt, i^ 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 



Quad Butt. H 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. H 



Hds 
In. 



X2 



Yi 
Y% 



Yb 

Yb 
Yb 
Yb 



Long 
joint 



Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Triple Butt. 
Triple Butt. 
Triple Butt. 
Triple Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 
Quad Butt. 

Quad Butt. 
Quad Butt. 
Quad Butt. 





.M c 






v.,H 
















6S 


.1?: 


Q'^ 


at 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


1 


4 


Wi 


4 


Wa 


4 


Wa 


4 


1'4 


4 


IM 


4 


Wa 


4 


\Va 


4 


Wa 


4 


IM 


5 


m 


D 


l'/2 





m 


5 


lJ/2 


5 


m 


5 


Wo 


6 


9 


6 


2 


6 


o 


6 


9 


6 


-9 


6 


O 


6 


O 


6 


9 


6 


9 


6 


9 


6 


O 


6 


■■> 


6 


o 


6 


9 


6 


9 


7 


9 




O 


7 


9 




9 


7 


'1 




9 










2H 
W2 
2U 



■^Y2 
W2 

Wt 
"-Yi 

2M 

2 3^' 

W2 

2M 
2M 

W2 

2H 

•W2 



2J^ 
2M 
2J/2 



^-Yi 

2Y2 

2J^ 

■2Y2 

2Y2 
2Y2 
2Y2 



*Coatesville Boiler Works, Philadelphia, Pa. 

tFor heating boilers, a boiler horsepower is assumed in this table to be equivalent to 12 sq. ft. of heating surface 
JA boiler of 48-in. diameter and larger has a manhole in the front head below the tubes in addition to the regular manhole 
in the upper part of the shell or front head 

330 



Table 28-24. Properties of Air 



Temper- 
ature, 
deg. 
fahr. 


Vol. 
of dry 
air 
with 
unity 
at 32 
deg. 
fahr. 


Cubic 
feet 
per 

lb. of 
air 


Weight 

per cu. 

ft. of 

dry 

air 

in lb. 


Zero 


0.935 


11.58 


0.0864 


12 


0.960 


11.87 


0.0842 


22 


0.980 


12.14 


0.0824 


32 


1.000 


12.40 


0.0807 


42 


1.020 


12.64 


0.0791 


52 


1.041 


12.88 


0.0776 


60 


1.057 


12.39 


0.0764 


62 


1.061 


13.13 


0.0761 


70 


1.078 


13.34 


0.0750 


72 


1.082 


13.39 


0.0747 


82 


1.102 


13.64 


0.0733 


92 


1.122 


13.90 


0.0720 


100 


1.139 


13.95 


0.0710 


102 


1.143 


14.14 


0.0707 


112 


1.163 


14.40 


0.0694 


122 


1.184 


14.65 


0.0682 


132 


1.204 


14.90 


0.0671 


142 


1.224 


15.15 


0.0660 


152 


1.245 


15.40 


0.0649 


162 


1.265 


15.65 


0.0638 


172 


1.285 


15.90 


. 0628 


182 


1.306 


16.17 


0.0618 


192 


1.326 


16.42 


0.0609 


202 


1.347 


16.67 


0.0600 


212 


1.367 


16.92 


0.0591 



0.267 
0.388 
0.522 
0.556 

0.754 
0.785 
1.092 
1.501 

1.929 
2.036 
2.731 
3.621 

4.752 

6.165 

7.930 

10.099 

12.758 
15.960 
19.828 
24.450 

29.921 



Elastic 

force 

of 


Cubic 

feet 

of 


vapor in 
in. of 
mer- 
cury 


vapor 
from 1 
lb. of 
water 


0.044 




0.074 




0.118 




0.181 


3289 



2252 
1595 
1227 
1135 



819 
600 
444 

356 
334 
253 
194 

151 

118 
93.3 
74.5 

59.2 
48.6 
39.8 

32.7 

27.1 



B.t.u. ab- 
sorbed per 
cu. ft. of air 
per deg. fahr. 



Dry 
air 



0.02056 
0.02004 
0.01961 
0.01921 

0.01882 
0.01847 
0.01818 
0.01811 

0.01777 
0.01767 
0.01744 
0.01710 

0.01690 
0.01682 
0.01651 
0.01623 

0.01596 
0.01571 
0.01544 
0.01518 

0.01494 
0.01471 
0.01449 
0.01426 

0.01406 



Sat. 
air 



0.02054 
0.02006 
0.01963 
0.01924 

0.01884 
0.01848 
0.01822 
0.01812 

0.01794 
0.01790 
0.01770 
0.01751 

0.01735 
0.01731 
0.01711 
0.01691 

0.01670 
0.01652 
0.01634 
0.01616 

0.01.598 
0.01580 



Cu. ft. of 
air raised 1 
deg. fahr. by 1 
b.t.u. 



Dry 

air 



48.5 
50.1 
51.1 
52.0 

53.2 
54.0 
55.0 
55.2 

56.3 
56.5 

57.2 



59.1 
59.5 
60.6 
61.7 

62.5 
63.7 
65.0 
66.2 

67.1 
68.0 
68.9 
69.5 

71.4 



Sat. 
air 



48.7 
50.0 
51.0 
51.8 

52.8 
53,8 
54.6 
54.7 

55.5 
55.8 
56.5 
57.1 

57.8 
57.8 
58.5 
59.1 



59. 
60. 
61. 



62.4 



63 
64 



Table 28-25. Volume and Weight of Air at Atmospheric Pressure at 
Temperatures Between 212 and 850 Deg. Fahr. 



Temperature, 

degrees 

fahrenheit 


Volume of 
one pound 

in 
cubic feet 


Weight one 
cubic foot 
in pounds 


Temperature, 

degrees 

fahrenheit 


Volume of 
one pound 

in 
cubic feet 


Weight one 
cubic foot 
in pounds 


Temperature, 

degrees 

fahrenheit 


Volume of 
one pound 

in 
cubic feet 


Weight one 
cubic foot 
in pounds 


212 


16.925 


. 059084 


320 


19.647 


. 050898 


550 


25.444 


.039302 


220 


17.127 


. 058388 


340 


20.151 


. 049625 


575 


26,074 


.038352 


230 


17.379 


. 057541 


360 


20.655 


. 048414 


600 


26.704 


. 037448 


240 


17.631 


. 056718 


380 


21.159 


.047261 


650 


27.964 


.035760 


250 


17.883 


.055919 


400 


21.663 


.046162 


700 


29 224 


. 034219 


260 


18.135 


. 055142 


425 


oo ^93 


. 044857 


750 


30.484 


. 032804 


270 


18.387 


. 054386 


450 


0.7 923 


. 043624 


800 


31 . 744 


.031502 


280 


18.639 


.053651 


475 


23.554 


. 042456 


850 


33.004 


.030299 


290 


18.891 


. 052935 


500 


24.184 


.041350 








300 


19.143 


.052238 


525 


24.814 


.040300 









331 



Table 28-26. Weight of Water at Temperatures Used in Physical 

Calculations 



Temperature, Degrees Fahrenheit 



Weight per 

cubic foot, 

pounds 



Weight per 

cubic inch, 

pounds 



At 32 degrees or freezing point at sea level . . . 
At 39.2 degrees or point of maximum density. 

At 62 degrees or standard temperature 

At 212 degrees or boiling point at sea level. . . 



62.418 


0.03612 


62.427 


0.03613 


62.355 


0.03608 


59.846 


0.03469 



Table 28-27. Volume and Weight of Distilled Water at Various 

Temperatures" 



Tem- 
per- 
ature, 
deg. 
fahr. 



32 

39.2 

40 

50 

60 
70 
80 
90 

100 
110 
120 
130 

140 
150 



Relative 

volume 

water at 39.2 

deg.= l 



1.000176 
1.000000 
1.000004 
1.00027 



00096 
00201 
00338 



1.00504 



00698 
00915 
01157 
01420 



1.01705 
1.02011 



Weight 

in lb. 

per 

cubic 

foot 


Tem- 
per- 
ature, 
deg. 
Jahr. 


62.42 


160 


62.43 


170 


62.43 


180 


62.42 


190 


62.37 


200 


62.30 


210 


62 22 


212 


62.11 


220 


62.00 


230 


61.86 


240 


61.71 


250 


61.55 


260 


61.38 


270 


61.20 


280 



Relative 

volume, 

water at 39.2 

deg. = l 



1.02337 
1 . 02682 
1 . 03047 
1.03431 



03835 
04256 
04343 
, 0469 

0515 
, 0562 
.0611 



1.0662 

1.0715 
1.0771 



Weight 

in lb. 

per 

cubic 

foot 



61.00 
60.80 
60.58 
60.36 

60.12 
59.88 
59.83 
59.63 

59.37 
59.11 
58.83 
58.55 

58.26 
57.96 



Tem- 
per- 
ature, 
deg. 
fahr. 



290 
300 
310 
320 

330 
340 
350 
360 

370 
380 
390 
400 

410 

420 



Relative 

volume, 

water at 39.2 

deg. = 1 



1.0830 
1 . 0890 
1.0953 
1.1019 

1.1088 
1.1160 
1 . 1235 
1.1313 

1.1396 



1483 
1573 
167 

177 
187 



Weight 


Tem- 


Relative 


in lb. 


per- 


volume, 


per 


ature, 


water at 


cubic 


deg. 


39.2 deg. 


foot 


fahr. 


= 1 


57.65 


430 


1.197 


57.33 


440 


1.208 


57.00 


450 


1.220 


56.66 


460 


1.232 


56.30 


470 


1.244 


55.94 


480 


1.256 


55.57 


490 


1.269 


55.18 


500 


1.283 


54.78 


510 


1.297 


54.36 


520 


1.312 


53.94 


530 


1.329 


53.5 


540 


1.35 


53.0 


550 


1.37 


52.6 


560 


1.39 



Weight 
in lb. 

per 
cubic 

foot 



52.2 
51.7 
51.2 
50.7 

50.2 
49.7 
49.2 
48.7 

48.1 
47.6 
47.0 
46.3 

45.6 
44.9 



* Marks and Da 



Table 28-28. Boilins; Point of Water at Various Altitudes 



Boiling point, 

degrees 

fahrenheit 


Altitude above 

sea level, 

feet 


Atmospheric 

pressure, 

pounds per 

square inch 


Barometer 

reduced 

to 32 degrees, 

inches 


Boiling point, 

degrees 

fahrenheit 


Altitude above 

sea level, 

feet 


Atmospheric 

pressure, 

pounds per 

square inch 


Barometer 

reduced 

to 32 degrees, 

inches 


184 


15221 


8.20 


16.70 


199 


6843 


11.29 


22.99 


185 


14649 


8.38 


17.06 


200 


6304 


11.52 


23.47 


186 


14075 


8.57 


17.45 


201 


5764 


11.76 


23.95 


187 


13498 


8.76 


17.83 


202 


5225 


12.01 


24.45 


188 


12934 


8.95 


18.22 


203 


4697 


12.26 


24.96 


189 


12367 


9.14 


18.61 


204 


4169 


12.51 


25.48 


190 


11799 


9.34 


19.02 


205 


3642 


12.77 


26.00 


191 


11243 


9.54 


19.43 


206 


3115 


13.03 


26.53 


192 


10685 


9.74 


19.85 


207 


2589 


13.30 


27.08 


193 


10127 


9.95 


20.27 


208 


2063 


13.57 


27.63 


194 


9579 


10.17 


20.71 


209 


1539 


13.85 


28.19 


195 


9031 


10.39 


21.15 


210 


1025 


14.13 


28.76 


195 


8481 


10.61 


21.60 


211 


512 


14.41 


29.33 


197 


7932 


10.83 


22.05 


212 


Sea Level 


14.70 


29.92 


198 


7381 


11.06 


22.52 











332 



Table 28-29. Pressures Corresponding to Given Heads of Water in Feet 

Water at maximum density. Temperature, 39.2 deg. fahr. 
h = head in feet. P= pressure in lb. per sq. inch = .443 h 



h 


P 


h 


P 


h 


p 


h 


P 


h 


P 


h 


p 


h 


p 


1 


.433 


16 


6.928 


31 


13.42 


46 


19.92 


61 


26.41 


76 


32.91 


91 


39.40 


2 


.866 


17 


7.361 


32 


13.86 


47 


20.35 


62 


26.85 


77 


33.34 


92 


39.84 


3 


1.299 


18 


7.794 


33 


14.29 


48 


20.78 


63 


27.28 


78 


33.77 


93 


40.27 


4 


1.732 


19 


8.227 


34 


14.72 


49 


91 22 


64 


27.71 


79 


34.21 


94 


40.70 


5 


2.165 


20 


8.660 


35 


15.15 


50 


21.65 


65 


28.14 


80 


34.64 


95 


41.13 


6 


2.598 


21 


9.09 


36 


15.59 


51 


22.08 


66 


28.58 


81 


35.07 


96 


41.57 


7 


3.031 


99 


9.53 


37 


16.02 


52 


22.52 


67 


29.01 


82 


35.51 


97 


42.00 


8 


3.464 


23 


9.96 


38 


16.45 


53 


22.95 


68 


29.44 


83 


35.94 


98 


42.43 


9 


3.897 


24 


10.39 


39 


16.89 


54 


23.38 


69 


29.88 


84 


36.37 


99 


42.87 


10 


4.330 


25 


10.82 


40 


17.32 


55 


23.81 


70 


30.31 


85 


36.80 


100 


43.30 


11 


4.763 


26 


11.26 


41 


17.75 


56 


24.25 


71 


30.74 


86 


37.24 






12 


5.196 


27 


11.69 


42 


18.19 


57 


24.68 


72 


31.18 


87 


37.67 






13 


5.629 


28 


12.12 


43 


18.62 


58 


25.11 


73 


31.61 


88 


38.10 






14 


6.062 


29 


12.56 


44 


19.05 


59 


25.55 


74 


32.04 


89 


38-54 






15 


6.495 


30 


12.99 


45 


19.48 


60 


25.98 


75 


32.47 


90 


38.97 







Table 28-30. Pressure, in Oiuices Per Square Inch Corresponding to 
Various Heads of Water, in Inches" 



Head 



Decimal parts of an inch 
.4 .5 








.06 


.12 


.17 


.23 


.29 


.35 


.40 


.46 


.52 


1 


.58 


.63 


.69 


.75 


.81 


.87 


.93 


.98 


1.04 


1.09 


2 


1.16 


1.21 


1.27 


1.33 


1.39 


1.44 


1.50 


1.56 


1.62 


1.67 


3 


1.73 


1.79 


1.85 


1.91 


1.96 


2 02 


2.08 


2.14 


2.19 


2.25 


4 


2.31 


2.37 


2.42 


2.48 


2.54 


2.60 


2.66 


2 72 


2.77 


2.83 


5 


2.89 


2.94 


3.00 


3.06 


3.12 


3.18 


3.24 


3.29 


3.35 


3.41 


6 


3.47 


3.52 


3.58 


3.64 


3.70 


3.75 


3,81 


3.87 


3.92 


3.98 


7 


4.04 


4.10 


4.16 


4.22 


4.28 


4.33 


4.39 


4.45 


4.50 


4.56 


8 


4.62 


4.67 


4.73 


4.79 


4.85 


4.91 


4.97 


5.03 


5.08 


5.14 


9 


5.20 


5.26 


5.31 


5.37 


5.42 


5.48 


5.54 


5.60 


5.66 


5.72 



*Suplee's Mechanical Engineers' Reference Book, published by J. B. Lippincott Co. 

Table 28-31. Comparison of Measures of Pressure and Weight f 



1 lb. per 
sq. in. 



1 oz. per 
sq. in. 



1 atmos- 
p h e r e = 
(14.7 lb. 
persq. in.) 



144 lb. per sq. ft. 

2.0416 in. mercury at 62 deg. fahr. 
2.309 ft. water at 62 deg. fahr. 
27.71 in. water at 62 deg. fahr. 

0.1276 in. mercury at 62 deg. fahr. 
1.732 in. water at 62 deg. fahr. 

2116.3 lb. per sq. ft. 
33.947 ft. water at 62 deg. fahr. 
30 in. mercury at 62 deg. fahr. 
29.922 in. mercury at 32 deg. fahr. 



1 in. water 
at 62 deg. 
fahr. 



0.03609 lb 
5.196 lb. per sq 



5774 oz. 
ft. 



per sq. in. 



ft. water 
at 62 deg. = 
fahr. 



0.433 lb. per sq. in. 
62.355 lb. per sq. ft. 



in. mer- f 0.491 lb. or 7.86 oz. per sq. in. 
cury at = ■! 1.132 ft. water at 62 deg. fahr. 
62 deg. fahr. [ 13.58 in. water at 62 deg. fahr. 



IKent's Mechanical Engineers' Pocket Book 



333 



Table 28-32. Conversion of Mercury and Vapor Pressures 

Inches of mercury to pounds per square inch 



Tenths 





1 


2 


3 


4 


5 


6 


7 


8 


9 


Inches 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 


Lb. Sq. in. 





0. 


0.49 


0.98 


1.47 


1.96 


2.46 


2.95 


3.44 


3.93 


4.42 


10 


4.91 


5.40 


5.89 


6.39 


6.88 


7.37 


7.86 


8.35 


8.84 


9.33 


20 


9.82 


10.32 


10.81 


11.30 


11.79 


12.28 


12.77 


13.26 


13.75 


14.24 


30 


14.74 


15.2 


15.7 


16.2 


16.7 


17.2 


17.7 


18.2 


18.7 


19.1 


40 


19.6 


20.1 


20.6 


21.1 


21.6 


22.1 


22.6 


23.1 


23.6 


24.1 


50 


24.6 


25.1 


25.5 


26.0 


26.5 


27.0 


27.5 


28.0 


28.5 


29.0 


60 


29.5 


30.0 


30.5 


30.9 


31.4 


31.9 


32.4 


32.9 


33.4 


33.9 


70 


34.4 


34.9 


35.4 


35.9 


36.3 


36.8 


37.3 


37.8 


38.3 


38.8 


80 


39.3 


39.8 


40.3 


40.8 


41.3 


41.8 


42.2 


42.7 


43.2 


43.7 


90 


44.2 


44.7 


45.2 


45.7 


46.2 


46.7 


47.2 


47.6 


48.1 


48.6 


100 


49.1 


49.6 


50.1 


50.6 


51.1 


51.6 


52.1 


52.6 


53.0 


53.5 









Pounds 


per square inch to inches of mercury 






Tenths 





1 


2 


3 


4 


5 


6 


7 


8 





Pounds 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 





0. 


2.0352 


4.0704 


6.10.56 


8.1408 


10.1760 


12.2112 


14.2464 


16.2816 


18.3168 


10 


20.352 


22.3872 


24 4224 


26.4576 


28.4928 


30.528 


32.. 5632 


34.5984 


36.6336 


38.6688 


20 


40.704 


42.7392 


44.7744 


46.8096 


48 . 8448 


50.8809 


52.91.52 


54.9504 


56.9856 


59.0208 


30 


61.056 


63.0912 


65.1264 


67.1616 


69.1968 


71.2.320 


73.2672 


75.3024 


77.3376 


79.3728 


40 


81.408 


83.4432 


85.4784 


87.5136 


89.5488 


91.5840 


93.6192 


95.6544 


97.6896 


99.7148 


50 


101.76 


103.795 


105.830 


107.865 


109.900 


111.9.36 


113.971 


116.006 


118.041 


120.077 


60 


122.11 


124.145 


126.180 


128.215 


130.250 


132.286 


134.321 


136.356 


138.391 


140.427 


70 


142.46 


144.495 


146.530 


148.565 


150.600 


152.636 


1.54.671 


156.706 


158.741 


160.777 


80 


162.81 


164.945 


166.880 


168.915 


170.9.50 


172.986 


175.021 


177.056 


179.091 


181.127 


90 


183.16 


185.195 


187.230 


189.265 


191.300 


193.336 


195.371 


197.406 


199.441 


201.476 


100 


203.53 


205.565 


207.600 


209.635 


211.670 


213.706 


215.741 


217.776 


219.811 


221.846 



Table 28-33. 


Comparison of Measures of Pressure 




Name of units 


Atmospheres 


On square 
inch 


Inches 
mercury at 
32 deg.fahr. 


Feet of 

water at 

60 deg. fahr. 


Millimeters 
of mercury 
at 32' fahr. 


Pounds per 
square foot 


Kilograms 

per square 

meter 


Atmosphere 


1. 
.068,03 
.033,42 
.029,47 

.001,316 

.000,472,6 
.000,096,77 


14.7 
1. 
.491,3 
.433,2 

.019,34 

.006,947 

.001,423 


29.922 
"2!036 
1. 
.881,8 

.039,37 
.014,13 
.002,895 


33.94 
2.309 
1.134 
1. 

.044,64 
.016,03 
.003.283 


760. 
51.7 
25.398 
22.399 

1. 

.359,2 
.073,-55 


2,116. 
143.946 
70.7 
62.35 

2.784 
1. 
.204,8 


10,333 


Pounds per square inch 
In. mercury at 32° fahr. . 
Feet of water at 60° fahr. . 
MilUmeters of mercury 

at 32° fahr 

Pounds per square foot. . 
Kilograms per sq. meter 


702.925 
345.331 
304.565 

13.596 
4.883 
1. 



Table 28-34. Reasonable Economic Performance of Stationary Steam Plants* 





Central station 


Mfg. power plants 


Heating plants 


Type of plant 


Large 

10,000 kw. 

and up 


Small 

2000-10,000 

kw. 


Small 

up to 100 

hp. 


Medium 

100-500 

hp. 


Large 

500-2000 

hp. 


Central 
1000 hp. 
and up 


Office 

and public 

bldgs. 


Residence 


Efficiency of boiler and 
Furnace in per cent 


70-76 


68-74 


60-70 


68-72 


68-74 


68-74 


50-70 


50-65 


Coal per hour in lb. 


Per kw-hr. 


Per 1 hp. 


Per boiler hp. 




2-3 1 2^-4 


5-8 


3-5 


2J4-4 


3-4 1 3-6 i 



* L. P. Breckenridge. Lecture on Fuel Conservation 



334 



Table 28-35. Weight in Pounds of One Gallon of Water at Temperatures from 

32 Deg. to 420 Deg. Fahr. 



Temp. 


wt. 


Temp. 


wt. 


Temp. 


Wt. 


Temp. 


Wt. 


32 


8.344 


105 


8.279 


185 


8.084 


270 


7.788 


35 


8.345 


110 


8.270 


190 


8.069 


280 


7.748 


39.2 


8.3454 


115 


8.260 


195 


8.053 


290 


7.707 


40 


8.345 


120 


8.250 


200 


8.037 


300 


7.664 


45 


8.345 


125 


8.239 


205 


8.021 


310 


7.620 


50 


8.343 


130 


8.229 


210 


8.005 


320 


7.575 


55 


8.341 


135 


8.218 


212 


7.998 


330 


7.527 


60 


8.337 


140 


8.206 


215 


7.988 


340 


7.486 


65 


8.333 


145 


8.193 


220 


7.971 


350 


7.429 


70 


8.329 


150 


8.181 


225 


7.954 


360 


7.376 


75 


8.323 


155 


8.168 


230 


7.937 


370 


7.323 


80 


8.317 


160 


8.155 


235 


7.929 


380 


7.267 


85 


8.311 


165 


8.141 


240 


7.920 


390 


7.211 


90 


8.304 


170 


8.127 


245 


7.893 


400 


7.152 


95 


8.296 


175 


8.113 


250 


7.865 


410 


7.085 


100 


8.288 


180 


8.099 


260 


7.828 


420 


7.032 



Table 28-36. Contents of Round Tanks in U. S. Gallons, for Each Foot in Depth 

To find capacity of a tank of any size: Given dimensions of a cylinder in inches, to find its 
capacity in U. S. gallons: Square the diameter, multiply by the length and by .0034 



Diameter 
Ft. In. 



Gallons, 

1 foot in 

depth 



1 

1 3 

1 6 

1 9 

2 
2 3 
2 6 
2 9 



5.8735 

9.1766 

13.2150 

17.9870 

23.4940 
29.7340 
36.7092 
44.4179 

52.8618 
62.0386 
73.1504 
82.5959 

93.9754 
106.1200 
118.9386 
132.5209 

146.8384 
161.8886 
177.6740 
194.1913 

211.4472 
229.4342 
248.1564 
267.6122 



Diameter 
Ft. In. 



Gallons, 

1 foot in 

depth 



7 

7 3 

7 6 

7 9 

8 
8 3 
8 6 
8 9 



11 
11 
11 
11 

12 
12 
12 
12 

13 
13 
13 
13 

14 
14 
14 
14 



287.8032 
308.7270 
330.3859 
352.7665 

375.9062 
399.7666 
424.3625 
449.2118 

710.6977 
743.3686 

776.7746 
810.9143 

848.1890 
881 . 3966 
917.7395 
954.8159 

992.6274 
1031.1719 
1070.4514 
1108.0645 

1151.2129 
1192.6940 
1234.9104 
1277.8615 



Diameter 
Ft. In. 



Gallons, 

1 foot in 

depth 



15 
15 
15 
15 

16 
16 
16 
16 

17 
17 
17 
17 



21 
21 
21 
21 

22 
22 
22 



18 

18 3 

18 6 

18 9 



1321.5454 
1365.9634 
1407.5165 
1457.0032 

1503.6250 
1550.9797 
1599.0696 
1647.8930 

1697.4516 
1747.7431 
1798.7698 
1850.5301 

1903 02.54 
1956.2537 
2010.2171 
2064.9140 

2590.2290 
2652.2532 
2715.0413 
2778.5486 

2842.7910 
2907.7664 
2973.4889 
3039.9209 



Diameter 
Ft. In. 



Gallons, 

1 foot in 

depth 



23 
23 
23 
23 

24 
24 

24 
24 

25 
25 

25 
25 



27 
27 
27 
27 

28 



28 



26 

26 3 

26 6 

26 9 



3107.1001 
3175.0122 
3243.6595 
3313.0403 

3383.1563 
3454.0051 
3525.5929 
3597.9068 

3670.9596 
3744.7452 
3819.2657 
3894.5203 

3970.5098 
4047.2322 
4124.6898 
4202.9610 

4281.8072 
4361.4664 
4441.8607 
4522.9886 

4604.8.517 
4686.4876 
4770.7787 
4854.8434 



335 



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3 



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c 



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^ 


be 


<;m 


o 


o 


CTv 




n 


s 


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o 


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i 


t^ 


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Uh 


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CO 




Oi 




N 


r^ 


K 


CO 




CO 


:3 
o 


(M 






<a 


CC 


-Q 


r- 


ca 


• — 


H 


c 



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•3 a 

2 2 



" a 
I S 

f 



to ^ 



ii 5 tJ 






Q. "^ 



2 »? 






o 

a 




-Tj-r-'^OOM^lOCOt-'MCOffOn^ 






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tfl 

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;::::::::::::::::::; :iS^§§§§222SS : : : : 








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d 


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0) 

•8 

d 

2^ 


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o o o o o o ^ rH f-i : .'.■:.':: : 




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b 




OOOOr-H-HClrO 




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^1 










d 

^1 


lOOiOOiOOmOLOOOOOOiOOOOOOOOOOOOOOOOOOOOOO 



336 



Table 28-38. Friction of Water in Pipes 

Giving velocity in feet per second, friction head in feet and friction loss in pounds per square inch 

for each 100 ft. of pipe discharging a given quantity of water in gallons 

per niinute (Weisbach Formula) 



0) 

3 

a 
S 

Pi 


•s? 






•SI 


•0 

J3 


[A d 


ai3 
■- a 


T3 

J3 


in d 


•SI 


■0 

s 


n d 
w — 


^1 


•0 

s 

J3 


" 9 
Ml 


d-o 
— d 


s 

.d 


o* 
"^ (fl 


m 


£•8 


d 


a " 


>■?, 


a 


a " 


£?S 


a 


p » 


>>S 


a 


d "" 


£■3 


d 


a " 


>.o 


a 


d . 


d 




k. 


*^ u 




v-i 


0*^ 


^ 


*j 


** 


>-• 


*^ 


^ 


W U 




*-• 




"S <u 


■S *£ 


■ x a> 


'71 '^ 


.2 ^ 


.S 9i 


•3 0) 


.z a> 


.S <D 


'o ^ 


.a Qi 


.S 0) 


'u ^ 


.s a> 


.S QJ 


'u !> 


.2 •£ 


.S 0) 


S 


8" 


" 


tSft 


g» 


■5£ 


Sa 


g» 


".S 


2 * 


0" 


■3JS 


tja 


0" 


"£ 


■S n 


g" 


".£ 


tSa 








































o 


> a, 


£.a 


&s 


>• P. 


£.S 


££ 


s 

> a 


£.5 


'&a 


II 


£.3 


&£ 


11 


£.s 


£5 


u S 

> a 


S.S 


'&a 


M"Pipe 


1" Pipe 


l}<i"Pipe 


li-i" Pi 


pe 


2" Pipe 


2H"Pipe 


1 
51 3.64 1 7.59 


3.3 


2.04 


1.93 


0.84 


1.30 


0.71 


0.31 


0.91 


0.27 


0.12 


0.491 0.092 


0.04 


0.244 


0.046 


0.02 


10 


7.28 1 29.90 


13.0 


i.08 


10.26 


3.16 


2.60 


2.41 


1.05 


1.82 


1.08 


0.47 


0.98 


0.277 


0.12 


0.666 


0,092 


0.04 


15 


10.92 ' 66.01 


28.7 


6.12 


16.06 


6.98 


3.90 


5.47 


2.38 


2.73 


2.23 


0.97 


1.47 


0.677 


0.25 


0.986 


0.185 


0.08 


20 


14.66 115.92 


50.4 


8.16 


28.29 


12.30 


5.20 


9.36 


4.07 


3.64 


3.81 


1.66 


2.04 


0.97 


0.42 


1.316 


0.323 


0.14 


25 


18.20 I18O.OO 


78.00 


10.20 


43.70 


19.00 


6.50 


14.72 


6.4 


4.56 


6.02 


2.62 


2.60 


1.43 


0.62 


1.646 


0.485 


0.21 


30 








12.24 


63.25 


27.60 


7.80 


21.04 


9.15 


5.46 


8.62 


3.75 


3.03 


2.09 


0.91 


1.97 


0.693 


0.30 


36 








14.28 


85.10 


37.00 


9.10 


28.52 


12.4 


6.37 


11.61 


5.06 


3.54 


2.76 


1.22 


2.29 


0,92 


0.40 


40 






16.32 


110.40 


48.00 


10.40 


37.03 


16.10 


7.28 


14.99 


6.52 


4.05 


3.68 


1.60 


2.62 


1.19 


0.63 


45 














11.70 


46.46 


20.2 


8.19 


18.74 


8.15 


4.66 


4.60 


1.99 


2.95 


1.49 


0.66 


60 














13.00 


67.27 


24.9 


9.10 


23.00 


10.00 


6.10 


5.61 


2.44 


3.30 


1.86 


0.81 


60 














15.6 


86.50 


37.0 


10.92 


32.95 


14.25 


6.12 


8.88 


3.50 


3.95 


2.70 


1.17 


70 














18.2 


114.0 


49.3 


12.74 


44.60 


19.30 


7.14 


11.09 


4.80 


4.60 


3.46 


1.60 


76 














19.5 


129.0 


56.1 


13.65 


61 .52 


22.4 


7.70 


12.23 


5.32 


4.93 


4.14 


1.80 


80 




















14.56 


68.46 


25.3 


8.16 


14.66 


6.30 


5.26 


4.62 


2.00 


90 




















16.38 


81.50 


35.26 


9.18 


18.02 


7.80 


6.91 


6.96 


2.68 


100 




















18.20 


89.70 


39.0 


10.2 


21.76 


9.46 


6.60 


7.36 


3.20 


125 


























12.80 


34.27 


14.9 


8.13 


11.24 


4.89 


150 


























16.3 


48.76 


21.2 


9.80 


16.10 


7.00 


175 
































11.43 


21.75 


9.46 


185 
































12.08 


24.50 


10.61 


200 
































13.06 


28.68 


12.47 


3" Pipe 


3}4" Pipe 


4" Pipe 


S" Pipe 


6" Pipe 


7" Pipe 


10 0.448 


0.046 0.02 






























15 0.672 


0.092f 0.04 


0.498- 0.046 


0.02. 


























20 0.896 


0.138 0.06 


0.664r 0.069 


0.03 


























25 1.12 


0.231: 0.10 


0.83 j 0.092 


0.04 


























30 1.345 


0.30 


0.13 


0.9961 0.138 


0.06 


























35 1.569 


0.393 


0.17 


1.163! 0.208 


0.09 


























40 1.790 


0.53 


0.23 


1.329i 0.264 


0.11 


1.04 


0.138 


0.06 




















45 2.016 


0.647 


0.28 


1.494 0.323 


0.14 


1.17 


0.1615 


0.07 




















50, 2.24 


0.80 


0.35 


1.66 0.393 


0.17 


1.30 


0.208 


0.09 




















60! 2.688 


1.155 0.50 


1.992 0.555 


0.24 


1.56 


0.30 


0.13 


0.88 


0.1166 


0.05 














70! 3.136 


1.385 0.60 


2.324 0.879 


0.38 


1.82 


0.439 


0.19 


1.04 


0.162 


0.07 














75: 3.360 


1.70 • 0.75 


2.490 0.913 


0.395 


1.95 


0.485 


0.21 


1.20 


0.174 


0.075 














801 3.584 


2.08 0.90 


2.6561 0.948 


0.41 


2.08 


0.680 


0.23 


1.28 


0.185 


0.08 














90 4.032 


2.54 1.10 


2.988! 1.247 


0.66 


2.34 


0.60 


0.26 


1.44 


0.208 


0.09 














100 4.480 


3.01 1.31 


3.320; 1.478 


0.64 


2.60 


0.763 


0.33 


1.60 


0.277 


0.12 


1.14 


0.116 


0.05 








125; 5.60 


4.57 


1.99 


4.15 1 2.219 


0.96 


3.26 


1.13 


0.49 


2.00 


0.393 


0,17 


1.42 


0.161 


0.07 








1601 5.80 


6.55 


2.85 


4.98 3.12 


1.35 


3.80 


1.59 


0.69 


2. 4010.. 578 


0.25 


1.71 


0.231 


0.10 


1.20 


0.093 


0.04 


1751 7.92 


8.85 


3.85 


5.81 4.208 


1.82 


4.45 


2.146 


0.93 


2.80;0.785 


0.34 


2.00 


0.302 


0.13 


1.38 


0.115 


0.05 


I85I 8.34 


9.94 


4.30 


6.14 


4.62 


2.00 


4.70 


2 484 


1.075 


2.96|0.84 


0.36 


2.11 


0.36 


0.156 


1.65 


0.13 


0.056 


200: 9.04 


11.54 


5.02 


6.64 


5.60 


2.38 


5.1 


2 82 


1.22 


3.20;0.972 


0.42 


2.28 


0.39 


0.17 


1.70 


0.162 


0.07 


250:11.28 


17.84 


7.76 


8.30 


8.55 


3.70 


6.4 


4.37 


1.89 


4.0011.50 


0.66 


2.80 


0.60 


0.26 


2.10 


0.277 


0.12 


26512.40 


20.09 


8.72 


8.80 


9.60 


4.15 


6.79 


6.46 


2.09 


4.241.69 


0.73 


3.03 


0.70 


0.303 


2.23 


0.31 


0.134 


30013.52 


25.76 11.20 


9.96 


11.63 


5.04 


7.60 


6.16 


2.66 


4.80 2.15 


0.93 


3.40 


0.85 


0.37 


2.40 


0.393 


0.17 



Hot water averages 8 lb. per gallon 

Horsepower required to raise water: — horsepower = quantity in cu. ft. per min. X height of lift in feet -^ 529.2 = quantity 
in gal. per min. X height of lift in feet -7- 3958.7 

When the temjwrature of water increases, the pressure of the water vapor decreases the theoretical lift, which at 150 deg; 
fahr. = 25.7 ft.; at 175 deg. = 18.5 ft., and at 200 deg. = 7.2 ft. 



337 



Table 28-39. Cost of Water at Stated Rates per 1000 Gallons 



Number 








Cost per 1000 Gallons 








of — 
cubic feet 


S Cents 


6 Cents 


8 Cents 


10 Cents 


IS Cents 


20 Cents 


25 Cents 


30 Cents 


20 


$0 007 


$0,009 


$0,012 


.$0,015 


$0,021 


$0,030 


$0,037 


$0,045 


40 


015 


0.018 


0.024 


0.0.30 


0.045 


0.060 


0.075 


0.090 


60 


0.022 


0.027 


0.036 


0.045 


0.066 


0.090 


0.112 


0.135 


80 


0.030 


0.036 


0.048 


0.060 


0.090 


0.120 


0.150 


0.180 


100 


0.037 


0.049 


0.060 


0.075 


0.111 


0.1.50 


0.187 


0.224 


200 


0.075 


0.090 


0.120 


0.1.50 


0.225 


0.299 


0.374 


0.449 


300 


0.112 


0.135 


0.180 


0.224 


0.336 


0.449 


0.561 


0.673 


400 


0.150 


0.180 


0.239 


0.299 


0.450 


0.598 


0.748 


0.898 


500 


0.188 


224 


0.299 


0.374 


0,564 


0.748 


0.935 


1.122 


600 


0.224 


0.269 


0.3.59 


0.449 


0.448 


0.898 


1.122 


1.346 


700 


0.262 


0.314 


0.419 


0.524 


0.786 


1.047 


1.309 


1.571 


800 


0.299 


0.350 


0.479 


0..598 


0.897 


1.197 


1.496 


1.795 


900 


0.337 


0.404 


0.539 


0.673 


1.011 


1 . 346 


1.683 


2.020 


1,000 


0..374 


0.449 


0.598 


0.748 


1.122 


1 . 496 


1.870 


2.244 


2,000 


0.748 


0.898 


1.197 


.496 


244 


2.992 


3.740 


4.488 


3,000 


1.122 


1.346 


1.795 


2.244 


3.366 


1 488 


5.610 


6.732 


4,000 


1 . 496 


1 . 795 


2.393 


2.992 


4.488 


5.849 


7.480 


8.976 


5,000 


1.870 


2.244 


2.992 


3^740 


5.610 


7.480 


9.350 


11.220 


6,000 


2.244 


2.692 


3.590 


4.488 


6.732 


8.976 


11.220 


13.464 


7,000 


2.618 


3.141 


4.189 


5.236 


7.8.54 


10.472 


13.090 


15.708 


8.000 


2.992 


3.. 590 


4.787 


5.984 


8.976 


11.968 


14.961 


17.953 


9,000 


3^366 


4.039 


5.385 


6.732 


10.098 


13.164 


16.831 


20.197 


10,000 


3.74 


4.488 


5.984 


7.480 


11.122 


14 961 


18.701 


22.441 


20,000 


7.48 


8.976 


11.968 


14.961 


22.443 


29.992 


37.402 


44.882 


30,000 


11.22 


13.46 


17.95 


22.44 


,33.664 


44.88 


.56 10 


67.32 


40,000 


14.96 


17.95 


23.94 


29.92 


14.885 


59.84 


74.81 


89.77 


50,000 


18.70 


22.44 


29.92 


37^40 


.56.103 


74.80 


93.50 


112.20 


60,000 


22,44 


26.92 


35.90 


44.88 


67.323 


89.76 


112.20 


134.64 


70,000 


26.18 


31.41 


41.89 


.52.36 


78.543 


104.72 


130.90 


157.08 


80,000 


29.92 


35.90 


47.87 


59.84 


89.766 


119.68 


149.61 


179.53 


90,000 


33.66 


40.39 


.53.85 


67.32 


100.986 


134.61 


168.31 


201.97 


100,000 


37.40 


44.88 


59.84 


74.80 


111.22 


149.61 


187.01 


224.41 


200,000 


74.81 


89.76 


119.68 


149.61 


224.43 


299.22 


374.02 


448.82 


300,000 


112.20 


134.64 


179.53 


224.41 


3.36.64 


448^83 


.561.03 


673.24 


400,000 


149.61 


179. 53 


239.37 


299.22 


448.85 


598.44 


748.05 


897.66 


500,000 


187.01 


224.41 


299.22 


374.02 


561.03 


748.05 


935.06 


1122.07 


600,000 


224.41 


269.29 


.3.59.06 


448.83 


673.23 


897.66 


1122.07 


1346.49 


700,000 


261 . 81 


314.18 


418.90 


.523.63 


785,43 


1047.27 


1309.08 


1570.88 


800,000 


299 22 


359 . 06 


478.75 


.598.44 


897.66 


1196.88 


1496.10 


1795.32 


900.000 


336^62 


403.94 


538. 59 


673.24 


1009.86 


1346.49 


1683.11 


2019.73 


1,000,000 


374.02 


448.83 


.598.44 


748.05 


1122.06 


1498.10 


1870.12 


2244.15 


Table 28-40. Water Conversion Factors 


U. S. gallons 




X 8..33 


= pounds 


5. Cubic feet of water (39.2°) X 


62.427 


= pounds. 


U. S. gallons 




X 0.13368 = cubic ft. Cubic feet of water (39.2°) X 


7.48 


= U.S.gal. 


U. S. gallons 




X231.00 


= cubicin. Cubic feet of water (39.2°) X 


0.028 


= tons. 


U. S. gallons 




X 3.78 


= liters. 


Pounds of water 


X 


27.72 


= cubic in. 


Cubic inches of water (39.2' 


')X 0.0361.30 = pounds 


i. Pounds 


i of water 


X 


0.01602 


= cubic ft. 


Cubic inches of water (39.2' 


')X 0.004329 = U.S. gal. Pound. 


5 of water 


X 


0.12 


= U.S. gal. 


Cubic inches of water (39.2 


°)X 0.576384 = ounces 













338 



Table 28-41. Classification of Coals * 



1 cu. ft. of anthracite coal weighs 5.5 to 66 lb. 
1 " " " bituminous " " 50 to 55 lb. 
1 " " " semi-bituminous coal weighs 48 to 53 lb. 



Name of coal 



Percentages of combustible 



Fixed carbon 



Volatile matter 



B.t.u. per pound 
of combustible 



Anthracite 97.0 to 92.5 

Semi-anthracite 92 . 5 to 87 . 5 

Semi-bituminous 87 . 5 to 75 . 

Bituminous, East 75 . to 60 . 

West 65.0 to 50.0 

Lignite 50 . and under 



S.Oto 7.5 
7.5 to 12.5 
12.5 to 25.0 
25.0 to 40.0 
35.0 to 50.0 
50.0 and over 



14,600 to 14,800 
14,700 to 15,500 
15,500 to 16,000 
14,800 to 15,300 
13,500 to 14,800 
11,000 to 13,.500 



* Harding and Willard, Mechanical Equipment of Buildings. Published by John Wiley & Sons 

Table 28-42. Names and Sizes of Bituminous or Soft Coal f 

For "Domestic" soft coals there are no uniform names and sizes, but they are marketed in the various 
states under about these classes: 

Screenings usually smallest sizes. 

Duff goes through Ig-in. screen. 

No. 3 Nut goes through IJ^-in. screen, over ^i-in. screen. 

No. 2 Nut goes through 2-in. screen, over IJ^-in. screen. 

No. 1 Domestic Nut goes through 3-in. screen, over 1}^ or 2-in. screen. 

No. 4 Washed goes through ?i-in. screen, over ]/i-m. screen. 

No. 3 Washed Chestnut goes through \}4,-m. screen, over 5^-in. screen. 

No. 2 Washed Stove goes through 2-in. screen, over IM-in. screen. 

No. 1 Washed Egg goes through 3-in. screen, over 2-in. screen. 

No. 3 Roller Screened Nut goes through IJ/^-in. screen, over 1-in. screen. 

No. 2 RoUer Screened Nut goes through 2-in. screen, over l}^-in. screen. 

No. 1 Roller Screened Nut goes through 3,^-in. screen, over 2-in. screen. 

Egg goes through 6-in. screen, over 3-in. screen. 

Lump or Block goes through 6-in. screen, or over. 

Run-of-Mine in fine and large lumps. 

Pocahontas Smokeless: generally sized as: Nut, Egg, Lump, and Mine-Run. 

t Harding and Willard 

Table 28-43. Heat Values of Bitiuninous Coals % 
From selected free-burning and caking soft fuels taken from Bulletin No. 332, U. S. Geological Survey, and 

Bulletin No. 23, U. S. Bureau of Mines 



State 



Test 
No. 



Kind of fuel 



County 



B.t.u. 
per lb. 
dry coal 



Alabama 375 

Alabama 484 

Arkansas 293 

Arkansas 308 

Arkansas 340 

Georgia 481 

Illinois 448 

Illinois 511 

Illinois 509 

Indiana 428 

Indiana 435 

Indiana 464 

Indian Territory 437 

Indian Territory 449 

Kansas 311 

Kentucky 434 



Soft— caking. Bibb 13,671 

Soft — free burning Jefferson 14,447 

Soft — caking Sebastian 13,705 

Semi-anthracite — caking Johnson 14,125 

Lignite Quachita 9,549 

Soft — free burning Chattooga 12,865 

Soft— free burning WiUiamson 12,920 

Soft briquettes St. Clair 13,271 

Soft — caking Saline 13,621 

Soft — free burning Greene 13,099 

Soft— caking Pike 13,545 

Soft briquettes Parke 11,930 

Soft — free burning 13,932 

Semi-anthracite 14,682 

Soft — free burning Linn 12,343 

Soft — free burning Union 14,026 



X Harding and Willard 



339 



Table 28-44. Heat Values of Bituminous Coals* — Continued 

From selected free-burning and caking soft fuels taken from Bulletin No. 332, U. S. Geological Survey and 

Bulletin No. 23, U. S. Bureau of Mines 



State 



Test 
No. 



Kind of fuel 



County 



B.t.u. 
per lb. 
dry coal 



Maryland 490 

Maryland 518 

Missouri 319 

Montana 477 

New Mexico 392 

New Mexico 387 

Ohio 483 

Pennsylvania 473 

Pennsylvania 499 

Pennsylvania 514 

Tennessee 409 

Tennessee 368 

Tennessee 363 

Texas 291 

Utah 404 

Virginia 482 

Virginia 507 

Washington 290 

Washington 359 

West Virginia 305 

West Virginia 439 

Wyoming 399 

Wyoming 400 



Soft — free burning Allegany 14,515 

Soft bricfuettes Allegany 14,717 

Soft^aking Randolph 11,747 

Lignite — free burning Carbon 11,628 

Soft — caking Colfax 13,059 

Soft— free burning Colfax 12,721 

Soft — free burning Belmont 13,381 

Soft — caking Indiana 14,240 

Soft — free burning Cambria 14,119 

Soft briquettes Westmoreland 14,382 

Soft briquettes Claiborne 14,092 

Soft — free burning Campbell 14,008 

Soft— caking Grundy 13,257 

Lignite — free burning Wood 11,131 

Soft — free burning Summit 12,586 

Anthracite — free burning Montgomery 12,679 

Soft — caking Tazewell 14,177 

Subbit — free burning King 11,772 

Soft— free burning Kittitas 12,996 

Soft — free burning Marion 13,964 



Soft — caking Kanawha. 

Soft — free burning Carbon. . . 

Subbit — ^free burning Unita. . . . 



13,995 
12,222 
12,488 



Note — These values were obtained at the St. Louis Testing Plant from 139 samples of coal. The 
heating values of the various coals were established by " actually burning one gram of the air-dried coal in 
oxygen in a Mahler-bomb calorimeter." These values in B.t.u. give the theoretical maximum thermal 
value of soft coals 

♦Harding & Willard 

Table 28-45. Names and Sizes of Anthracite or Hard Coal t 



Names of sizes 



Will pass through 



Will not pass through 



Buckwheat No. 1 1 

No. 2 ..: / 

or Rice '. 

Pea ; 

Chestnut, or Nut 

Stove or Range 

Egg — in the East 

Large Egg — Chicago 

Small Egg — Chicago 

Broken, or Grate 



}^-in. mesh 

M-in. mesh 
^-in. mesh 
\]/i-in. mesh 
IM-in. mesh 
2J/^-in. mesh 
4 -in. mesh 
2J^-in. mesh 
4 -in. mesh 



l^-ia. mesh 

J/^-in. mesh 
J/2-in. mesh 
Ji-in. mesh 
IJ^-in. mesh 
l?4-in. mesh 
2%-in. mesh 
2 -in. mesh 
2}^-in. mesh 



t Harding and Willard 



Table 28-46. Calorific Value of Coal 

Where a complete analysis of the coal is not obLaiiiable the following formula may be used: B.t.u. per lb. = 144 [100 — (w-|- a)] 
- 10.8 wc, where w and a are the percentapes of water and ash, and c is a constant varyingr with the amount of water. When w < 
3%, = 4; when w is between 3 and 4.5%, c = 6; w bet. 4.5 and 8.5%, c = 12; w bet. 8.5 and 12%, c = 10; w bet. 12 and 20%. 
c-=8; w bet. 20 and 28%, c = 6; w > 28%, c = 4. Also, when C and Gi are the percentages of fixed and volatile carbon, respec- 
tively, and H the percentage of hydrogen, E.t.u. per lb. = (14,600 C + 20,390 Ci + 62,000 H) + 100 

340 



Table 28-47. Composition and Heat Values of Anthracite Coal 



Locality 



Fixed 
car- 
bon 



Vola- Mois- 

tile ture 



Sul- 
pliur 



B.t.u. 

per lb. 

of dry 

coal 



Anthracite 

Pennsylvania 78 . 60 

Buckwheat 81. 32 

Wilkes-Barre 76. 94 

Scranton 79. 23 

Scranton 84.46 

Cross Creek 89. 19 

Lehigh Valley 75.20 

Lykens Valley 76 . 94 

Lykens VaUey 81.00 

Wharton 86.40 

Buck Mt 82.66 

Beaver Meadow . 88.94 

Lackawanna 87 . 74 

Rhode Island 85. 00 

Arkansas 74. 49 

Semi-Anthracite 

Pennsylvania, Loyalsock 83 . 34 

Bernice 82.52 

Bernice . 89.39 

Wilkes-Barre 88.90 

Lycoming Creek 71 . 53 

Virginia, Natural Coke 75. 08 

Arkansas 74 . 06 

Indian Territory 73.21 

Maryland, Easby 83. 60 







14.80 


0.40 




3.84 


3.88 


10.96 


0.67 


12,200 


6.42 


1.34 


15.30 




11,801 


3.73 


3.33 


13.70 


• . • < 


12,149 


5.37 


0.97 


9.20 


.... 


12,294 


1.96 


3.62 


5.23 





13,723 


7.36 


1.44 


16.00 




12,423 


6.21 






.... 


15,300 


5.00 








15,300 


3.08 


3.7i 


6.22 


6.58 


15,000 


3.95 


3.04 


9.88 


0.46 


15,070 


2.38 


1.50 


7.11 


0.01 




3.91 


2. 12 


6.35 
7.00 


0.12 
0.90 




14.73 


i.52 


9.26 




13,217 


8.10 


1.30 


6.23 


1.03 


15,400 


3.56 


0.96 


3.27 


0.24 


15,050 


8.S6 


0.97 


9.34 


1.04 


15,475 


7.68 




3.49 




14,199 


13.84 


0.67 


13.96 


6.03 




12.44 


1.12 


11.38 


0.47 




14.93 


1.35 


9.66 






13.65 


5.11 


8.03 


i.is 


13,662 


16.40 








11,207 



*Harding & Willard 



Table 28-48. Weight of Materials 

Dry woods 



Weight in 
Material lb. of one 

cu. ft. 

Ash 43-53 

Beech 43-53 

Birch 40-46 

Boxwood 57-83 

Cork 15 

Ebony 70-83 

Elm 34-45 



Weight in 
Material lb. of one 

cu. ft. 

Fir, Spruce 30-44 

Greenheart 70 

Hornbeam 47 

Larch 31-37 

Lignum-vitae 83 

Mahogany — Honduras. 35 

" Spanish . . 53 



Weight in 
Material lb. of one 

cu. ft. 

Oak — American red 54 

" English 48-58 

Pin(^-red 30-44 

white 27-34 

yellow 29-41 

Teak 41-55 



Stones, earth, etc. 



Weight in 
Material lb. of one 

cu. ft. 

Asphaltum 64-112 

Brick — common 100-125 

fire 137-150 

Cement— Portland 80-90 

Clay 120 

Concrete 120-140 

Earth 77-120 

Glass — crown 156 



Weight in 
Material lb. of one 

cu. ft. 

Glass— flint 187 

plate 169 

Granite 164-175 

Gravel 90-125 

Grindstone 134 

Lime — quick 52 

Limestone and marbles 150-179 

Mortar— hardened .. . . 88-118 



Weight in 
Material lb. of one 

cu. ft. 

Mud— dry and close . . . 80-110 
wet and fluid . . . 104-120 

Sand— dry 88-110 

wet 118-129 

Sandstone 130-170 

Victoria stone (crushed "1 

granite, Portland ce- > 144 
ment. silica) ) 



341 



Table 28-49. Weight of Materials — Continued 
Metals and Alloys 



Material 



Specific 
gravity 



Weight in lb. 

of one 

cu. ft. cu. in. 



Cu. in. 

in one 

lb. 



Aluminum — cast 

wrought 

" bronze 

Antimony 

Arsenic 

Bismuth 

{from 
to 
average 

" Muntz metal 

" naval (rolled) 

" sheet 

" wire 

{from 
to 
average 

Copper — cast 

hammered 

" sheet 

" wire 

Gold (pure) 

" standard 22 carat fine 

(Gold 11— Copper 1) 

{from 
to 
average 
I from 

Iron — wrought Uo 

[average 

Lead — cast 

sheet . . 

Manganese 

Nickel — cast 

" rolled 

Platinum 

Silver 

(from 
to 
average 

Tin 

White Metal (Babbitt's) 

Zinc — cast 

" sheet 



2.569 


160 


.093 


10.80 


2.681 


167 


.097 


10.35 


7.787 


485 


.281 


3.56 


6.712 


418 


.242 


4.13 


5.748 


358 


.207 


4.83 


9.827 


612 


.354 


2.82 


7.868 


490 


.284 


3.53 


8.430 


525 


.304 


3.29 


8.109 


505 


.292 


3.42 


8.221 


512 


.296 


3.37 


8.510 


530 


.307 


3.26 


8.462 


527 


.305 


3.28 


8.558 


533 


.308 


3.24 


8.478 


528 


.306 


3.27 


8.863 


552 


.319 


3.13 


8.735 


544 


.315 


3.18 


8.622 


537 


.311 


3.22 


8.927 


556 


.322 


3.11 


8.815 


549 


.318 


3,15 


8.895 


554 


.321 


3.12 


19.316 


1203 


.696 


1.44 


17.502 


1090 


.631 


1.59 


6.904 


430 


.249 


4.02 


7.386 


499 


.266 


3.76 


7.209 


464 


.260 


3.85 


7.547 


470 


.272 


3.56 


7.803 


486 


.281 


3.68 


7.707 


480 


.278 


3.60 


11.368 


708 


.410 


2.44 


11.432 


712 


.412 


2.43 


8.012 


499 


.289 


3.46 


8.285 


516 


.299 


3.35 


8.687 


541 


.313 


3.19 


21. 516 


1,340 


.775 


1.29 


10. 517 


655 


.379 


2.64 


7.820 


487 


.282 


3.55 


7.916 


493 


.285 


3.51 


7.868 


490 


.284 


3.53 


7.418 


462 


.267 


3.74 


7. 322 


456 


.264 


3.79 


6.872 


428 


.248 


4.04 


7.209 


449 


.260 


3.85 



Table 28-50. Specific Heat and Densities of Building Materials ' 



Building materials 



Specific 
heat 



Brickwork . 1950 

Concrete 0.2700 

Masonry . . 2159 

Plaster." 2000 

Pinewood 4670 



Building materials 



Specific 
heat 



Oakwood 0.5700 

Birch 4800 

Glass 1977 

Steel 1165 



Densities in 16 per cu. ft. 

.Stonework 160 

Wood 40 

Slate 170 

Plaster 90 



* Harding and Willard 



.142 



Table 28-51. Specific Heats of Various Substances f 



Solids 



Temperature,* „ .„ 

degrees Speciflc 

fahrenheit '•««' 

Copper 59-460 0. 0951 

Gold 32-212 . 0316 

Wrought iron 59-212 . 1152 

Cast iron 68-212 . 1200 

Stee\ (hard) 68-208 . 1175 

Steel (soft) 68-208 . 1165 

Zinc 32-212 .0935 

Brass (vellow) 32 .0883 



Temperature,* 

degrees Specific 

fahrenheit heat 

Glass (normal ther. 16"'). • • • 66-212 0. 1988 

Lead 59 .0299 

Platinum 32-212 .0323 

Silver 32-212 .05.59 

Tin 105-64 .0518 

Ice 5040 

Sulphur (newly fused) .2025 



Liquids 



Temperature,* c-„--fi„ 
degrees S?"'^'^ 

fahrenheit 



Water. . 
Alcohol 



59 

/32 

1176 

Mercury 32 

Benzol j^So 

Glycerine 59-102 

Lead (melted) to 360 



heat 



1 . 0000 
0.5475 
.7694 
.3346 
.4066 
.4502 

.0410 



Temperature,* gpecific 

* degrees *; , 

fahrenheit "^^ 

Sulphur (melted) 246-297 0. 2350 

Tin (melted) . 637 

Sea-water (sp. gr. 1.0043) 61 . 980 

Sea-water (sp. gr. 1.0463) 64 . 903 

Oil of turpentine 32 .411 

Petroleum 64-210 . 498 

Sulphuric acid 68-133 . 3363 

Olive oil 309 



Gases 



Air 

Oxygen . . . 
Nitrogen . . 
Hydrogen . 



Tempera- 
ture,* 
degrees 
fahrenheit 


Specific 
heat at 
constant 
pressure 


Specific 
heat at 
constant 
volume 


32-392 
5.5-405 
32-392 
54-388 


0.2375 
.2175 
.2438 

3.4090 


0.1693 
.1553 
.1729 

2.4141 



Tempera- Specific Specific 

ture,* heat at heat at 

degrees constant constant 

fahrenheit pressure volume 



Carbon monoxide. . . . 41-208 

Carbon dioxide 52-417 

Methane 64-406 

Blast-fur. gas (approx.) 

Flue gas (approx.) 



0. 



2425 


0.1728 


2169 


.1535 


5929 


.4505 


2277 




2400 





* When one temperature alone is given the "true" specific heat h given; otherwise the value is the "mean" specific heat for the 
range of temperature aiven 
tHarding and Willard 

Table 28-52. Tensile Strength of Materials 

Average value in pounds per square inch 



Antimony 1053 

Aluminum — castings 15000 

sheet 24000 

bars 28000 

Brass — yellow 26880 

Bronze — cast 34000 

delta metal— cast 44800 
" rolled 67200 

gun metal 32000 

phosphor 40000 

" manganese 62720 

Tobin 78500 

Copper — cast 22400 

sheet 30240 

wire 40000 



Cast Steel. 



.80000 



Gold 20384 

Iron— cast 25000 

" 18000 

wrought 4.5000 

Lead— cast 1800 

rolled sheet 3320 

Platinum wire 53000 

Puddled semi-steel 

35000 to 42000 

Silver— cast 40000 

Steel— cast 60000 to 80000 

forgings. . . 60000 to 95000 

Tin— cast 3360 

Zinc — cast 3360 

sheet 15680 



Woods 

Ash 11000 to 17000 

Beech 11500 to 18000 

Cedar 10300 to 11400 

Chestnut 10500 

Elm 13000 to 13489 

Hemlock 8700 

Hickory 12800 to 18000 

Locust 20500 to 24800 

Maple 10500 to 10584 

Oak— white 10253 to 19500 

Pine— white 10000 to 12000 

yellow 12600 to 19200 

Spruce 10000 to 19500 

Walnut, black... 9286 to 16000 



.34.S 



Table 28-53. Lineal Expansion of Solids at Ordinary Temperatures 

(Tabular values represent increase per foot per 100-deg. increase 
in temperature, fahr. or cent.) 



Substance 



Temperature 
conditions* 
deg. fahr. 



Coefficient per 100 
deg. fahr. 



Coefficient per 100 
deg. cent. 



Brass (cast) 

Brass (wire) 

Copper 

Glass (English flint) . 

Glass (French flint) . 

Gold. 

Granite (average) . . . 
Iron (cast) 



Iron (soft forged) . 

Iron (wire) 

Lead 

Mercury 



Platinum. '. 

Limestone 

Silver 

Steel (Bessemer rolled, hard) . 

Steel (Bessemer rolled, soft) . . 

Steel (cast, French) 

Steel (cast annealed, English) 



32 to 212 


32 to 212 


32 to 212 


32 to 212 


32 to 212 


32 to 212 


32 to 212 


104 


to 212 


32 to 212 


32 to 212 


32 to 212 


104 


32 to 212 


104 


to 212 


to 212 


104 


104 



001042 


.001875 


001072 


.001930 


000926 


.001666 


000451 


.000812 


000484 


. 000872 


000816 


.001470 


000482 


. 000868 


000589 


.001061 


000634 


.001141 


000800 


. 001440 


001505 


.002709 


0099841 


.017971t 


000499 


. 000899 


000139 


. 000251 


001067 


.001921 


00056 


.00101 


00063 


.00117 


000734 


. 001322 


000608 


. 001095 



* Where range of temperature is given, coeflicient is mean over range 
t CoefiGcient of cubical expansion 



Table 28-54. Deciir^al^^qiiivalents of Fractions of an Inch 



Fractions 




3^ 


■^ 




iV 




H 


^ 


A 


, . 


7 










M 


9 








A 




11 






32 







Decimals 



.015625 
.03125 
.046875 
.0625 

.078125 
.09375 
.109375 
.125 

.140625 
.15625 
.171875 
.1875 

.203125 
.21875 
.234375 
.25 

.265625 
.28125 
.296875 
.3125 

.328125 
.34375 



'■■ 'Fraiipons 



Decimals 



.359375 
.375 
.390625 
.40625 

.421875 
.4375 
.453125 
.46875 

.484375 
.5 

.515625 
.53125 

.546875 
.5625 
..578125 
.59375 

.609375 
.625 
.640625 
.65625 

.671875 
.6875 



Fractions 



.703125 
.71875 
.734375 
.75 

.765625 
.78125 
.796875 
.8125 

.828125 
.84375 
.859375 
.875 

.890625 
.90625 
.921875 
.9375 

.953125 
.96875 
.984375 
1.00 



344 



Table 28-55. Decimals of a Foot for Inches and Fractions of an Inch 

Inch 0" 1" 2" 3" 4" S" 6" 7" 8" 9" 10" 11" 

-. ^ 

.0833 .1667 .2500 .3333 .4167 .5000 .5833 .6667 .7.500 .8333 .9167 

A .0026 .0859 .169S .2526 .3359 .4193 .5026 .5859 .6693 .7526 .8359 .9193 

^ .0052 .0885 .1719 .2552 .3385 .4219 .5052 .5885 .6719 .75.52 .8385 .9219 

^ .0078 .0911 .1745 .2578 .3411 .4245 .5078 .5911 .6745 .7578 .8111 .9245 

Vs .0104 .0937 .1771 .2604 .3437 .4271 .5104 .5937 .6771 .7604 .8437 .9271 

A -0130 .0964 .1797 .2630 .3464 .4297 .5130 .5964 .6797 .7630 .8464 .9297 

^ .0156 .0990 .1823 .2656 .3490 .4323 .5156 .5990 .6823 .7656 .8490 .9323 

^ .0182 .1016 .1849 .2682 .3516 .4349 .5182 .6016 .6849 .7682 .8516 .9349 

M -0208 .1042 .1875 .2708 .3542 .4375 .5208 .6042 .6875 .7708 .8542 .9375 

^ .0234 .1068 .1901 .2734 .3568 .4401 .52,34 .6068 .6901 .7734 .8.568 .9401 

A .0260 .1094 .1927 .2760 .3594 .4427 .5260 .6094 .6927 .7760 .8594 .9427 

a .0286 .1120 .1953 .2786 .3620 .4453 .5286 .6120 .6953 .7786 .8620 .9453 

% .0312 .1146 .1979 .2812 .3646 .4479 .5312 .6146 .6979 .7812 .8646 .9479 

M .0339 .1172 .2005 .2839 .3672 .4505 .5339 .6172 .7005 .7839 .8672 .9505 

1^ .0365 .1198 .2031 .2865 .3698 .4531 .5365 .6198 .7031 .7865 .8698 .9531 

a .0391 .1224 .2057 .2891 .3724 .4557 .5391 .6224 .7057 .7891 .8724 .9557 

}4 .0417 .1250 .2083 .2917 .3750 .4583 .5417 .6250 .7083 .7917 .8750 .9583 

a .0443 .1276 .2109 .2943 .3776 .4609 .5443 .6276 .7109 .7943 .8776 .9609 

^ .0469 .1302 .2135 .2969 .3802 .4635 .5469 .6302 .7135 .7969 .8802 .9635 

If .0495 .1328 .2161 .2995 .3828 .4661 .5495 .6328 .7161 .7995 .8828 .9661 

^ .0521 .1354 .2188 .3021 .3854 .4688 .5521 .6354 .7188 .8021 .88.54 .9688 

a .0547 .1380 .2214 .3047 .3880 .4714 .5547 .6380 .7214 .8047 .8880 .9714 

H .0573 .1406 .2240 .3073 .3906 .4740 .5573 .6406 .7240 .8073 .8906 .9740 

U .0599 .1432 .2266 .3099 .3932 .4766 .5599 .6432 .7266 .8099 .8932 .9766 

K .0625 .1458 .2292 .3125 .3958 .4792 .5625 .6458 .7292 .8125 .89.58 .9792 

If .0651 .1484 .2318 .3151 .3984 .4818 .5651 .6484 .7318 .8151 .8984 .9818 

M .0677 .1510 .2344 .3177 .4010 .4844 .5677 .6510 .7344 .8177 .9010 .9844 

M .0703 1536 .2370 .3203 .4036 .4870 .5703 .6536 .7370 .8203 .9036 .9870 

Ji .0729 .1562 .2396 .3229 .4062 .4896 .5729 .6562 .7396 '8229 .9062 .9896 

.5755 .6.589 .7422 .8255 .9089 .9922 
.5781 .6615 .7448 .8281 .9115 .9948 
.5807 .6641 .7474 .8307 .9141 .9974 
1.0000 



Table 28-56. Decimals of a Foot Equivalent to Inches and Fractions 

of an Inch 



0729 


.1562 


.2396 


.3229 


.4062 


.4896 


0755 


. 1.589 


.2422 


. 3255 


.4089 


.4922 


0781 


.1615 


.2448 


.3281 


.4115 


.4948 


0807 


.1641 


.2474 


.3307 


.4141 


.4974 



Inches 


0" 


M" 


M" 


H" 


H" 


%" 


%" 


Vs" 








.01042 


. 02083 


.03125 


.04166 


.05208 


. 06250 


.07292 


1 


.0833 


.0937 


.1042 


.1146 


.1250 


.1354 


. 1459 


.1563 


2 


.1667 


.1771 


.1875 


.1979 


.2083 


.2188 


.2292 


.2396 


3 


.2500 


.2604 


.2708 


.2813 


.2917 


.3021 


.3125 


.3229 


4 


.3333 


.3437 


.3542 


.3646 


.3750 


3854 


.3958 


.4063 


5 


.4167 


.4271 


.4375 


.4479 


.4583 


.4688 


.4792 


.4896 


6 


.5000 


.5104 


.5208 


.5313 


.5417 


.5521 


.5625 


.5729 


7 


.5833 


.5937 


.6042 


.6146 


.6250 


.6354 


.6459 


.6563 


8 


.6667 


.6771 


.6875 


.6979 


.7083 


.7188 


.7292 


.7396 


9 


.7500 


.7604 


.7708 


.7813 


.7917 


.8021 


.8125 


.8229 


10 


.8333 


.8437 


.8542 


.8646 


.8750 


.8854 


.8958 


.9063 


11 


.9167 


.9271 


.9375 


.9479 


.9583 


.9688 


.9792 


.9896 



345 



Table 28-57. Circumferences and Areas of Circles 
Advancing by Eighths 



Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


A 


. 04909 


. 00019 


2.ii 


8.44,30 


5.6727 


7. 


21.991 


.38,485 


14. M 


44.768 


1,59.48 


■h 


.09818 


.00077 


^4 


8.6394 


5.9396 


Ys 


22.384 


39.871 


Ys 


45.160 


162, 30 


A 


.14726 


.00173 


M 


8.8357 


6.2126 


M 


22.776 


41 . 282 


Yi 


45.553 


165.13 


T^ 


.19635 


. 00307 


y% 


9.0321 


6,4918 


Ys 


23.169 


42,718 


Ys 


45.946 


167.99 


A 


.29452 


. 00690 


15 
16 


9.2284 


6,7771 


Yi 


23., 562 


44,179 


Yi 


46.3.38 


170.87 


Vs 


.39270 


.01227 








Ys 


23.9,55 


45,664 


Ys 


46.731 


173.78 


^ 


.49087 


.01917 


3. 


9.4248 


7.0686 


Yi 


24.347 


47.173 








A 


. 58905 


. 02761 


1^ 


9.6211 


7.3662 


Ys 


24.740 


48.707 


15. 


47.124 


176.71 


3^ 


. 68722 


. 03758 


J 8 


9.8175 


7.6699 








Ys 


47,517 


179.67 








3 
16 


10.014 


7.9798 


8. 


25.1.33 


50.265 


Yi 


47.909 


182.65 


H 


. 78540 


.04909 


M 


10.210 


8.29,58 


Ys 


25., 525 


51.849 


Ys 


48.302 


185.66 


A 


.88357 


.06213 


h 


10.407 


8.6179 


M 


25.918 


,53.456 


Yi 


48.695 


188.69 


A 


.98175 


.07670 


% 


10.603 


8.9462 


Ys 


26.311 


55.088 


Ys 


49.087 


191,75 


11 

32 


1.0799 


.09281 


^ 


10.799 


9.2806 


Yi 


26.704 


,56.745 


Yi 


49.480 


194,83 


H 


1.1781 


.11045 


Vi 


10.996 


9.6211 


Ys 


27.096 


,58.426 


Yi 


49.873 


197.93 


¥ 


1.2763 


.12962 


9 
16 


11.192 


9.9678 


Yi 


27.489 


60.132 










1.3744 


. 1,5033 


Yi 


11. 388 


10.321 


Ys 


27.882 


61 . 862 


16. 


,50.265 


201 . 06 


a 


1.4726 


. 17257 


H 


11, 585 


10.680 








Vs 


,50.6,58 


204.22 








% 


11.781 


11.045 


9, 


28.274 


63.617 


Yi 


51.051 


207.. 39 


^2 


1.5708 


. 19635 


M 


11.977 


11.416 


Ys 


28.667 


65, 397 


Ys 


51 . 414 


210.60 


H 


1.6690 


.22166 


Vi 


12.174 


11.793 


Yi 


29.060 


67.201 


Yi 


51 . 836 


213.82 


A 


1,7671 


.24850 


16 


12.370 


12 177 


Ys 


29.452 


69.029 


Ys 


52.229 


217.08 


19 
32 


1.8653 


. 27688 








Yi 


29.845 


70.882 


Yi 


52.622 


220.35 


5^8 


1.9635 


. 30680 


4. 


12.. 566 


12.566 


Ys 


.30.2,38 


72 . 760 


Ys 


53,014 


223,65 


21 

37 


2.0617 


. 33824 


T^ 


12.763 


12.962 


Yi 


30.631 


74.662 








11 


2.1598 


.37122 


J'8 


12.9.59 


13.364 


Ys 


31 . 023 


76.589 


17, 


53.407 


226.98 


M 


2.2580 


. 40574 


_3_ 
16 


13.155 


13.772 








Ys 


,53.800 


230.33 








M 


13.3,52 


14.186 


10. 


31.416 


78.540 


Yi 


54.192 


233.71 


M 


2.3562 


.11179 


A 


13.548 


14.607 


Ys 


31 . 809 


80.516 


% 


.54.. 585 


237.10 


ft 


2.4544 


. 47937 


% 


13.744 


15.033 


Yi 


,32.201 


82.516 


Yi 


54.978 


240.53 




2.5525 


. 51849 


^ 


13 941 


15.466 


Ys 


32, 594 


84.541 


Ys 


55.371 


243.98 


32 


2.6507 


..5.5914 


Y2 


14.137 


15.904 


Yi 


.32.987 


86, 590 


Yi 


55.763 


247.45 


Fs 


2.7489 


.60132 


9 
16 


14.334 


16. 349 


Ys 


.33.379 


88.664 


Ys 


56.156 


250.95 


29 
32 


2.8471 


.64504 


Y% 


14., 530 


16.800 


Yi 


33.772 


90.763 








tf 


2.9452 


. 69029 


H 


14.726 


17.257 


Ys 


34.165 


92.886 


18. 


56., 549 


254.47 


fi 


3.0434 


. 73708 


Y^ 


14.923 


17.721 








Ys 


,56.941 


258.02 








if 


15.119 


18.190 


11. 


34.. 558 


95.0.33 


Yi 


57.3,34 


261, 59 


1. 


3.1416 


.7854 


y% 


15.315 


18.665 


Ys 


.34.9.50 


97.205 


% 


,57.727 


265.18 


16 


3.3379 


.8866 


13 
16 


15.512 


19.147 


Yi 


35.343 


99.402 


Yi 


58.119 


268.80 


Ks 


3.5343 


.9940 








% 


35.736 


101 . 62 


Ys 


.58.512 


272.45 


A 


3.7306 


1.1075 


5. 


15.708 


19.635 


Yi 


36.128 


103.87 


Yi 


,58.905 


276.12 


J€ 


3.9270 


1.2272 


1^ 


15.904 


20.129 


Ys 


36, 521 


106.11 


Ys 


,59.298 


279.81 


A 


4.1233 


1 . 3530 


Yi 


16.101 


20.629 


Yi 


36.914 


108.43 








?^ 


4.3197 


1 . 4849 


3 
T6 


16.297 


21.1.35 


Ys 


37.306 


110.75 


19. 


59.690 


283.53 


A 


4. 5160 


1 . 6230 


M 


16.493 


21 648 








Ys 


60.083 


287.27 


y2 


4.7124 


1.7671 


A 


16.690 


22.166 


12. 


37.699 


113.10 


Yi 


60.476 


291.04 


^ 


4.9087 


1.9175 


Yi 


16.886 


22.691 


Ys 


38.092 


115.47 


Ys 


60.868 


294.83 


Yi 


5.1051 


2.0739 


A 


17.082 


23.221 


Yi 


38.485 


117.86 


Yi 


61.261 


298.65 


H 


5.3014 


2.2,365 


M 


17.279 


23.7,58 


Ys 


38.877 


120.28 


Ys 


61 . 654 


302.49 


M 


5.4978 


2.40,53 


9 


17.475 


21.301 


Yi 


39.270 


122.72 


Yi 


62.046 


306.35 


it 


5.6941 


2, 5802 


Yi 


17.671 


21 8,50 


Ys 


.39.663 


125^19 


Ys 


62.439 


310.24 


K 


5.8905 


2.7612 


11 

16 


17.868 


25 . 406 


Yi 


40.0.55 


127.68 








if 


6.0868 


2.9483 


Y^ 


18.064 


25.967 


Ys 


40.448 


130.19 


20. 


62.832 


314.16 








13. 
16 


18.261 


26, 535 








Ys 


63.225 


318.10 


9 


6.2832 


3.1416 


y% 


18.4.57 


27.109 


13. 


40.841 


132.73 


Yi 


63.617 


322.06 


"'a 


6.4795 


3.3410 


M 


18.653 


27.688 


Ys 


41 . 233 


135.30 


?-8 


64.010 


326.05 


y% 


6.6759 


3, 5466 








Yi 


41 . 626 


137.89 


Yi 


64.403 


330.06 


A 


6.8722 


3.7583 


6. 


18.850 


28.274 


% 


42.019 


140.50 


Ys 


64.795 


334.10 


M 


7.0686 


3.9761 


J-8 


19.242 


29.465 


Yi 


42.412 


143.14 


Yi 


65.188 


338.16 


A 


7.2649 


4.2000 


Y4. 


19.635 


30.680 


Ys 


42.804 


145.80 


Ys 


65.581 


342.25 


?^ 


7.4613 


4.4301 


% 


20.028 


31.919 


Yi 


43 197 


148.49 








A 


7.6576 


4.6664 


Yi 


20.420 


33.183 


Ys 


43.590 


151.20 


21. 


65.973 


346.36 


j^ 


7.8540 


4.9087 


Ys 


20.813 


34.472 








Yk 


66.366 


3,50.50 


T^ 


8.0503 


5.1572 


H 


21 . 206 


35.785 


14. 


43.982 


1,53.94 


Yi 


66.7,59 


354.66 


^ 


8.2467 


5.4119 


Ys 


21.. 598 


37.122 


Ys 


44.375 


1,56.70 


Ys 


67.152 


358.84 



346 



Table 28-57. Circumferences and Areas of Circles 
Advancing by Eighths — Continued 



Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


21. Ji 


67.544 


363.05 


28.^4' 


90.321 


649.18 


.36. 


113.097 


1017.9 


13. J^ 


135.874 


1469.1 


'A 


67.937 


367.28 


Vs 


90.713 


654.84 


}8 


113.490 


1025.0 


Vs 


136.267 


1477.6 


H 


68.330 


371, 54 








Vi 


113.883 


1032.1 


V2 


136.659 


1486.2 


Vs 


68.722 


375.83 


29. 


91.106 


660.52 


8 8 


114.275 


1039.2 


Vs 


137.052 


1494.7 








J-8 


91.499 


666.23 


Vi 


114.668 


1046.3 


Vi 


137.445 


1503.3 




69.115 


380.13 


% 


91.892 


671.96 


?8 


115.061 


10.53.5 


Vs 


137.837 


1511.9 


'Vs 


69.508 


.384.46 


Js 


92.284 


677.71 


% 


115.454 


1060.7 








M 


69.900 


388.82 


Vi 


92.677 


683.49 


Vs 


115.846 


1068.0 


44. 


138.230 


1.520.5 


Vs 


70.293 


.393.20 


Vs 


93.070 


689.30 








Vs 


138.623 


1.529.2 


K 


70.686 


397.61 


H 


93. 162 


695.13 


37. 


116.239 


1075.2 


Vi 


139.015 


1537.9 


H 


71.079 


402.04 


Is 


93.855 


700.98 


^8 


116.632 


1082.5 


Vs 


139.408 


1.546.6 


H 


71.471 


406.49 








Vi 


117.024 


1089.8 


Vi 


139.801 


1.555.3 


H 


71.864 


410.97 


,30. 


94.248 


706.86 


H 


117.417 


1097.1 


Vs 


140.194 


1.564.0 








Vs 


94.640 


712.76 


Vt 


117.810 


1104.5 


Vi 


140, 586 


1.572.8 


23. 


72.257 


415.48 


Va 


95.033 


718.69 


Vs 


118.202 


1111.8 


Vs 


140.979 


1581.6 


Vs 


72.649 


420.00 


Vs 


95.426 


724.64 


H 


118. 596 


1119,2 








H 


73.042 


424.56 


Vi 


95.819 


730.62 


Vs 


118.988 


1126.7 


15. 


141.372 


1590.4 


y% 


73.435 


129.13 


Vs 


96.211 


736.62 








Vs 


141.764 


1599.3 


Yi 


73.827 


133.74 


H 


96.604 


742.64 


38. 


119.381 


1134.1 


Vi 


142.1.57 


1608.2 


y% 


74.220 


138.36 


Vs 


96.997 


748.69 


Vs 


119.773 


1141.2 


Vs 


142.550 


1617.0 


M 


74.613 


443.01 








Vi 


120.166 


1149.2 


V2 


142.942 


1626.0 


Vi 


75.006 


447.69 


31. 


97.389 


7,54.77 


?8 


120.. 5.59 


11,56.6 


Vs 


143.335 


1634.9 








Vs 


97.782 


760.87 


Vi 


120.951 


1164.2 


% 


143.728 


1643.9 


24. 


75.398 


452.39 


H 


98.175 


766.99 


Vs 


121 . 344 


1171.7 


Vs 


144.121 


1652.9 


Vi 


75.791 


457.11 


Vs 


98.. 567 


773.14 


Vi 


121.737 


1179.3 








M 


76.184 


161.86 


Vi 


98.960 


779.31 


Vs 


122.129 


1186.9 


16. 


144.513 


1661 . 9 


y% 


76.576 


466.64 


Vs 


99.353 


785.51 








Vs 


144.906 


1670.9 


Vi 


76.969 


171.44 


V 


99.746 


791.73 


.39. 


122. 522 


1191.6 


Vi 


145.299 


1680.0 


Vs 


77.362 


476.26 


Vs 


100.1.38 


797.98 


Is 


122 '915 


1202.3 


Vs 


145.691 


1689.1 


H 


77.754 


481.11 








- Vi 


123.308 


1210.0 


V2 


146.084 


1698.2 


- Vs 


78.147 


485.98 


32. 


100., 531 


804.25 


H 


123.700 


1217.7 


Vs 


146.477 


1707.4 








Ys 


100.924 


810.54 


V2 


124.093 


1225.4 


Vi 


146.869 


1716.5 


25. 


78.. 540 


190 87 


H 


101.316 


816.86 


Vs 


124.486 


1233.2 


Vs 


147.262 


1725.7 


Vs 


78.933 


495.79 


% 


101.709 


823.21 


Vi 


124.878 


1241.0 








Vi 


79.325 


,500.74 


Vi 


102.102 


829. 58 


Vs 


125.271 


1248.8 


17. 


147.6.55 


1734.9 


Vs 


79.718 


.505.71 


Vs 


102.494 


835.97 








Vs 


148.048 


1744.2 


Vi 


80.111 


510.71 


Vi 


102.887 


812.39 


10. 


125.664 


12.56.6 


Vi 


148.440 


1753.5 


Vs 


80. 503 


515.72 


Vs 


103.280 


848.83 


?8 


126.056 


1264.5 


Vs 


148.833 


1762.7 


H 


80.896 


.520.77 








Vi 


126.449 


1272.4 


V2 


149.226 


1772.1 


Vs 


81 . 289 


.525.84 


33. 


103.673 


8.55.30 


?8 


126.842 


1280.3 


Vs 


149.618 


1781.4 








Vs 


104.065 


861.79 


Vi 


127.235 


1288.2 


Vi 


1.50.011 


1790.8 


26. 


81.681 


.530.93 


Vi 


104.4.58 


868.31 


Vs 


127.627 


1296.2 


Vs 


150.404 


1800.1 


Vs 


82.074 


.536.05 


?8 


104.851 


874.85 


Vi 


128.020 


1301.2 








Va 


82.467 


541 . 19 


Vi 


105.243 


881.41 


• Vs 


128.413 


1312.2 


18. 


150,796 


1809.6 


Vs 


82.860 


.546.35 


Vs 


105.636 


888.00 








Vs 


151.189 


1819.0 


Vi 


83.252 


551 . 55 


Vi 


106.029 


894.62 


11. 


128.805 


1320.3 


Vi 


151.. 582 


1828.5 


Vs 


83.645 


.5.56.76 


H 


106.421 


901.26 


Vs 


129.198 


1328.3 


Vs 


151.975 


1837.9 


Vi 


84.038 


.562.00 








Vi 


129.591 


1336.4 


V2 


152.367 


1847.5 


Vs 


84.430 


567.27 


34. 


106.814 


907.92 


?8 


129.983 


1344.5 


Vs 


152.760 


1857.0 








J-8 


107.207 


914.61 


Vi 


130.376 


13.52.7 


Vi 


153.153 


1866.5 


27. 


84.823 


.572.56 


Vi 


107.600 


921.32 


5-8 


130.769 


1360.8 


Vs 


153.545 


1876.1 


Vs 


85.216 


577.87 


H 


107.992 


928.06 


Vi 


131.161 


1369.0 








Vi 


85.608 


.583.21 


Vi 


108.385 


931.82 


Vs 


131 . 5.54 


1377.2 


19. 


153.938 


1885.7 


Vs 


86.001 


.588.57 


Vs 


108.778 


9U.61 








Vs 


154.331 


1895.4 


Vi 


86.394 


.593.96 


H 


109.170 


918.42 


12. 


131.917 


1385.4 


Vi 


154.723 


1905.0 


Vs 


86.786 


.599.37 


H 


109., 563 


9,55.25 


y% 


132.340 


1393.7 


Vs 


155.116 


1914.7 


M 


87.179 


601.81 








Vi 


132 732 


1402.0 


V2 


155, 509 


1924.4 


Vs 


87.572 


610,27 


35. 


109.956 


962.11 


H 


133.125 


1410.3 


Vs 


155.902 


1934.2 








Vs 


110.348 


969.00 


Vi 


133.518 


1118.6 


Vi 


156.294 


1943.9 


28. 


87.965 


615.75 


Vi 


110.741 


975.91 


Vs 


133.910 


1427.0 


Vs 


156.687 


1953.7 


Vs 


88.357 


621.26 


58 


111.134 


982.84 


% 


134.303 


1135.4 








Vi 


88.750 


626.80 


Vi 


1 11. 527 


989.80 


Vs 


134.696 


1443.8 


.50. 


157.080 


1963.5 


Vs 


89.143 


632.36 


Vs 


111.919 


996.78 














Vi 


89.. 535 


6.37.94 


Vi 


112.312 


1000.38 


13. 


135.088 


14.52.2 








Vs 


89.928 


643. 55 


Vs 


112.705 


1010.8 


Vs 


135.481 


1460.7 









347 



Table 28-58. Fractional Equivalents, Powers and Roots of Numbers 



Num- 
ber 


Frac, 
equiv. 


Square 
root 


Cube 
root 


Square 


Cube 




1 

X 




Num- 
ber 


Frac. 
equiv. 


Square 
root 


Cube 
root 


Square 


Cube 




d 

H 
O 














> 














> 


.01 
.0156 
.02 
.03 


^ 


.1 

.125 

.1414 

.1732 


.2154 
.25 
.2714 
.3107 


.0001 
. 0002441 
.0004 
.0009 


.000001 
. 000003815 
. 000008 
. 000027 


.802 
1.003 
1.134 
1.389 


.3281 
.33 

34 

3438 


21 
64 

11 

32 


.5728 
.5745 
.5831 
.5863 


.6897 
.6910 
.6980 
.7005 


.1077 
.1089 
.1156 
.1182 


. 03533 
. 03594 
.03930 
. 04062 


4,594 

4.607 
4.677 
4.702 


.0313 
.04 
.0469 
.05 


A 
^ 


.1768 

.2 

.2165 

.2236 


.3150 
.3420 
. 3606 
. 3684 


. 0009766 
.0016 
.002197 
.0025 


. 00003052 
. 000064 
.000103 
.000125 


1.418 
1.604 
1 . 756 
1.793 


.35 
3594 
.36 
.37 


a 


.5916 
.5995 
.6 
.6083 


. 7017 
.7110 
.7114 
.7179 


.1225 
1292 

'.vm 

.1369 


, 04288 
, 04:641 
.04666 
. 05065 


4.745 
4.808 
4.812 
4.879 


.06 
.0625 
.07 
.0781 


1^ 

5 
64 


.2449 
.25 
.2646 
.2795 


.3915 
.3968 
.4121 
.4275 


.0036 
. 003906 
. 0049 
.006104 


. 000216 
. 0002441 
. 000343 
. 0004768 


1.965 
2.005 
2 122 
2.242 


.375 
.38 
.39 
.3906 


25 
64 


.6124 
. 6164 
.6245 
.625 


.7211 

. 7243 
.7306 
.7310 


. 1406 
. 1444 
.1521 
.1526 


. 05273 
. 05487 
. 05932 
.05960 


4.911 

4.944 
5,009 
5.013 


.08 
.09 
.0938 
.1 


'i- 


.2828 
.3 

.3062 
.3162 


.4309 
.4481 
.4543 
.4642 


. 0064 
.0081 
. 008789 
.01 


. 000512 
. 000729 
. 0008240 
.001 


2.269 
2.406 
2.456 
2.537 


.4 

. 4063 
.41 

.42 


'a 


.6325 
.6374 
. 6403 
.6481 


.7368 
. 7406 
. 7429 
.7489 


,16 
.1650 
,1681 
,1764 


.64 

. 06705 
, 06892 
, 07409 


5.072 
5.112 
5.135 
5.198 


.1094 
.11 
.12 
.125 


7 
64 

Vs 


.3307 
.3317 
. 3464 
.3536 


.4782 
.4791 
.4932 
.5 


.01196 
.0121 
.0144 
.01562 


. 001308 
.001331 
. 001728 
. 001953 


2.653 
2.660 
2.778 
2.836 


.4219 
.43 
. 4375 

. 44 


27 
64 

7 
16 


.6495 
.6557 
.6614 
.6633 


.75 
.7548 
.7591 
.7606 


.1780 
. 1849 
.1914 
.1936 


. 07508 
.07951 
. 08374 
.08518 


5.209 
5,259 
5,305 
5,320 


.13 
.14 
. 1406 
.15 


^ 


.3606 
.3742 
.375 
.3873 


.5066 
.5193 
.5200 
.5313 


.0169 
.0196 
.01978 
.0225 


. 002197 
. 002744 
. 002781 
.003375 


2.892 
3.001 
3.008 
3.106 


.45 
. 4531 
.46 
. 4688 


29 
64 

lA 
32 


.6708 
.6732 
.6782 
.6847 


.7663 
,7681 
.7719 
.7768 


.2025 
.2053 
,2116 
.2197 


,09113 
. 09304 
. 09734 
.1030 


5.380 
5.399 
5.440 
5,491 


.1563 
.16 
.17 
.1719 


_5_ 
32 


.3953 
.4 

.4123 
.4146 


.5386 
. 5429 
. 5540 
.5560 


. 02441 
. 0256 
.0289 
. 02954 


.003815 
. 004096 
.004913 
. 005077 


3.170 
3.208 
3 307 
3.325 


.-47 
48 

. 481 1 
.49 


31 
6T 


.6856 
.6928 
.6960 

.7 


,7775 
.7830 
.7853 
,7884 


.2209 
. 2304 
,2346 
.2401 


,1038 
.1106 
,1136 
.1176 


5,498 
5,557 
5,582 
5,614 


.18 

.1875 

.19 

.20 


A 


.4243 
.433 
.4359 
.4472 


.5646 
. 5724 
. 5749 
.5848 


. 0324 
.03516 
.0361 
.04 


. 005832 
. 006592 
. 006859 
.008 


3.403 
3.473 
3.496 
3.587 


.5 
51 

.5156 
.52 


V2 


.7071 
.7141 
.7181 
.7211 


.7937 
.7990 
,8019 
,8042 


,25 
,2601 
,2658 
,2704 


.125 
,1327 
,1371 
.1406 


5,671 
5,728 
5,759 
5.784 


.2031 
.21 
.2188 
'■'2 


7 
32 


.4507 
. 4583 
.4677 
.4690 


.5878 
.5944 
.6025 
.6037 


.04126 
.0441 
. 04785 
.0484 


. 008381 
. 009261 
.01047 
. 01065 


3.615 
3.675 
3.751 
3.762 


.53 
.5313 
..54 
. 5469 


1 7 
32 

.35 
64 


.7280 
.7289 
. 7349 
.7395 


,8093 
,8099 
,8143 
,8178 


.2809 
.2822 
'2916 
.2991 


.1489 
,1499 
. 1.575 
,1636 


5.839 
5.846 
5,894 
5.931 


.23 
.2344 
.24 
.25 


M 

k 


.4796 
.4841 
.4899 
.5 


.6127 
.6165 
.6215 
.6300 


.0529 
. 05493 
.0576 
.0625 


.01217 
.01287 
.01382 
.01563 


3.846 
3.883 
3.929 
4.010 


.55 
.56 
.5625 

.57 


9 

re 


.7416 
.7483 

.75 ; 

.7550 


,8193 
1,8243 
,8255 
,8291 


. 3025 
.3136 
.3164 
.3249 


.1664 
.1756 
,1780 
.1852 


5.948 
6.002 
6.015 
6.055 


.26 
.2656 

.27 
.28 


H 


.5099 
.5154 
.5196 
.5292 


.6383 
.6428 
. 6463 
. 6542 


.0676 
, 07056 
.0729 
,0784 


.01758 
. 01874 
. 01968 
.02195 


4.090 
4.134 
4.167 
4.244 


.5781 
.58 
.59 
.5938 




.7603 
.7616 
.7681 
.7706 


,8330 
,8340 
,8387 
, 8405 


.3342 
,3364 
, 3481 
.3525 


.1932 
.1951 
. 2054 
.2093 


6.098 
6.108 
6.161 
6.180 


.2813 
.29 
.2969 
.30 




.5303 
.5385 
.5448 

.5477 


.6552 
.6619 
.6671 
. 6694 


.07910 
.0841 
. 08814 
.09 


. 02225 
. 02439 
.02617 
.027 


4.253 
4.319 
4.370 
4.393 


.6 

. 6094 
.61 
.62 


a 


.7746 
.7806 
.7810 
.7874 


,8434 
,8478 
,8481 
,8527 


.36 
.3713 
.3721 
,3844 


.2160 
.2263 
,2270 
.2383 


6,212 
6.261 
6.264 
6.315 


.31 

.3125 

.32 


5 
16 


.5568 
.5590 
.5657 


.6768 
.6786 
.6840 


.0961 
. 09766 
.1024 


. 02979 
. 03052 
. 03277 


4.466 
4.483 
4.537 


.625 

.63 

.64 


% 


.7906 
.7937 
.8 


, 8550 
,8573 
.8618 


.3906 
,3969 
.4096 


,2441 
,2500 
,2621 


6.341 
6.366 
6.416 



348 



Table 28-58. Fractional Equivalents, Powers and Roots of Numbers — Continued 



Num- 
ber 



.6406 
.65 



Frac. 
equiv, 



6.563 


ki 


66 




67 
6719 


43 
64 


68 




6875 


a 


69 




70 




7031 


n 


71 




7188 


23 


72 




73 




7344 


U 


74 




75 


% 


76 




7656 


¥i 


77 




78 




7813 


^ 


79 




7969 


M 


8 




81 




8125 


M 


82 




8281 


S3 
64" 


83 




84 




8438 


fJ 


85 




8594 


S 


86 




87 




875 


'^ 


88 




89 




8906 


f^ 


9 




9063 


29 
3T 


91 




92 




9219 


AS 
61 


93 




9375 


^ 


94 




95 




9531 


a 



Square 
root 



Cube 
root 



. 8004 
.8062 
.8101 
. 8124 

.8185 
.8197 
. 8246 
.8292 

.8307 
.8367 
.8395 
. 8426 

. 8478 
.8485 
. 8544 
.8570 

.8602 
.8660 
.8718 
.875 

.8775 
.8832 
.8839 
.8888 

.8927 
. 8944 
.9 
.9014 

.9055 
.9100 
.9110 
.9165 

.9186 
.9219 
.9270 
.9274 

.9327 
.9354 
.9381 
. 9434 

.9437 
.9487 
.9520 
.9539 

. 9592 
.9601 
.9644 
.9682 

.9695 
.9747 
.9763 



.8621 
.8662 
.8690 
.8707 

. 8750 
. 87.59 
. 8794 
.8826 

.8837 
.8879 
.8892 
.8921 

. 8958 
.8963 
. 9004 
.9022 

.9045 
.9086 
.9126 
.9148 

.9166 
.920 
.9210 
. 9244 

.9271 
.9283 
.9322 
.9331 

.9360 
.9391 
.9398 
.9435 

.9449 
.9473 
.9507 
.9510 

.9546 
. 9565 
.9583 
.9619 

.9621 
.9655 
.9677 
.9691 

.9726 
.9732 
.9761 
.9787 

.9796 
.9831 
.9840 



Square 



.4104 
. 4225 
. 4307 
. 4356 

. 4489 
.4514 
.4624 

.4727 

.4761 
.49 
. 4944 
.5041 

.5166 
.5184 
. 5329 
.5393 

.5476 
.5625 
. 5776 
. 5862 

. 5929 
. 6084 
. 6104 
.6241 

.6350 
.64 
.6561 
.6602 

.6724 
. 6858 
.6889 
.7056 

.7120 

.7225 
.7385 
.7396 

.7569 
.7656 

.7744 
.7921 

.7932 
.81 
.8213 
.8281 

.8464 
.8499 
.8649 
.8789 

.8836 
.9025 
.9084 



Cube 



.2629 
.2746 
.2826 
.2875 

. 3008 
.3033 
.3144 
.3249 

. 3285 
.3430 
. 3476 
. 3579 

.3713 
.3732 
.3890 
.3961 

. 4052 
. 4219 
. 4390 
.4488 

. 4565 
. 4746 
. 4768 
. 4930 

.5060 
. 5120 
. 5314 
. 5364 

.5514 
.5679 
.5718 
.5927 

.6007 
.6141 
.6347 
.6361 

. 6585 
.6699 
.6815 
,7050 

.7065 
.7290 
.7443 
.7536 

.7787 
. 7835 
.8044 
.8240 

.8306 
.8574 
.8659 



> 



6.419 
6.466 
6.497 
6.516 

6.565 
6.574 
6.614 
6.650 

6.66 
6.710 
6.725 
6.758 

6.799 
6.805 
6.8.53 
6.873 

6.899 
6.946 
6.992 
7.018 

7.038 
7 083 
7.089 
7.129 

7.1.59 
7.174 
7.218 
7.229 

7.263 
7.298 
7.307 
7.351 

7.367 
7.394 
7.435 
7.438 

7.481 
7.. 502 
7.. 524 
7.566 

7.569 
7.609 
7.635 
7.651 

7.693 
7.701 
7.734 
7.766 

7.776 
7.817 
7.830 



Number 



.96 
.9688 
.97 
.98 

. 9844 

.99 
1. 
1.1 

1.2 

1.3 
1.4 
1.5 

1.6 
1.7 
1.8 
1.9 



2.1 

2 2 
2^3 

2.4 
2.5 
2.6 

2.7 

2.8 
2.9 
3. 
3.1 

3.2 
3.3 
3.4 
3.5 

3.6 
3.7 
3.8 
3.9 

4. 
4.1 
4.2 
4.3 

4.4 
4.5 
4.6 

4.7 

4.8 
4.9 
5. 



Frac. 
equiv 



Square 
root 



.9798 
. 9843 
. 9849 
.9899 

.992 
.9950 

1. 

1 . 049 

1 . 095 
1.14 
1.183 
1.225 

1 . 265 
1 . 304 
1 . 342 
1.378 

1 . 414 



449 
483 
517 



1 . 549 



581 

612 
643 



1.673 
1.703 
1.732 
1.761 

1.789 
1.817 
1.844 
1.871 

1.897 
1.924 



949 
975 



2. 

2' 025 
2.049 
2.074 

2.098 
2.121 
2.145 
2.168 

2.191 
2.214 
2.236 



Cube 
root 



. 9865 
. 9895 
.9899 
.9933 

.9948 
.996 

1. 

1.032 

1 . 063 
1.091 
1.119 
1 . 1145 

1.170 



193 
216 
239 



1.260 



281 
301 
320 



1 339 
1 . 357 
1.375 
1.392 

1 . 409 
1 . 426 
1 . 442 
1.458 

1.474 



489 
504 
518 



1.533 
1.547 
1.560 
1.574 

1.587 
1.601 
1.613 
1.626 



639 
651 
663 
675 

687 
698 
710 



Square 



.9216 
. 9385 
. 9409 
. 9604 

.9690 
.9801 



Cube 



21 



1 . 44 



69 
96 
25 



2.56 
2.89 
3.24 
3.61 

4. 

4.41 
4.84 
5.29 

5.76 
6.25 
6.76 
7.29 

7.84 
8.41 
9. 
9.61 

10.24 
10.89 
11.56 
12.25 

12.96 
13.69 
14.44 
15.21 

16. 
16.81 
17.64 
18.49 

19.36 
20.25 
21.16 
22.09 

23.04 
24.01 
25. 



. 8847 
.9091 
.9127 
. 9412 

.9538 
.9703 

1. 

1.331 

1.728 
2.197 
2.744 
3.375 

4.096 
4.913 
5.832 
6.859 

8. 

9.261 
10.65 
12.17 

13.82 
15.63 
17.58 
19.68 

21 . 95 
24.39 

27. 
29. 



79 



32.77 
35.94 
39.30 
42.88 

46.66 
50.65 
54.87 
59.32 

64. 
68.92 
74.09 
79.51 

85.18 
91.13 
97.34 
103.8 

110.6 
117.6 
125. 



H 
O 



7.8.58 
7.894 
7.899 
7.940 

7.957 
7.980 
8.021 
8.412 

8.786 
9.145 
9.490 
9.823 

10.14 
10.45 
10.76 
11.06 

11.34 
11.62 
11.90 
12.16 

12.43 
12.68 
12.93 
13.18 

13.42 
13.66 
13.89 
14.12 

14.35 
14.57 
14 79 
15.01 

15.22 
15.43 
15.64 
15.85 

16.04 
16.24 
16.44 
16.63 

16.82 
17.01 
17.20 
17.39 

17.57 
17.75 
17.93 



349 



Table 28-59. Comparison of Wire Gauges 
Thickness in decimals of an inch 



d 

4) 

s 

£5 


■ils 

o 


S 

bUZi 

pa 


1 

i 


ad 


c 


la 

V 

■ss 

E3 


d 






ll 
ia 


g 



cd 


ffld 


If 

-5 


1. 


0000000 






.490 


.500 




.5 


23 


. 02257 


.025 


. 0258 


.024 


.027 


. 028125 


000000 


. 5800 




.460 


.464 




.46875 


24 


. 02010 


.022 


. 0230 


.022 


.025 


.025 


00000 


.5165 




.430 


. 432 




. 4375 


25 


.01790 


.020 


. 0204 


.020 


.023 


.021875 


0000 


. 4600 


.454 


.3938 


.400 


. 454 


. 40625 


26 


. 01594 


.018 


.0181 


.018 


. 0205 


. 01875 


000 


. 4096 


.425 


. 3625 


.372 


.425 


.375 


27 


. 01420 


.016 


.0173 


.0161 


.0187 


.0171875 


00 


. 3648 


.380 


.3310 


.348 


.380 


. 34375 


28 


. 01264 


.014 


.0162 


.0148 


. 0165 


.015625 





. 3249 


.340 


.3065 


.324 


.340 


.3125 


29 


.01126 


.013 


.0150 


.0136 


. 0155 


. 0140625 


1 


.2893 


.300 


.2830 


.300 


.300 


. 28125 


30 


.01003 


.012 


.0140 


. 0124 


. 01372 


.0125 


2 


.2576 


.284 


.2625 


.276 


.284 


. 265625 


31 


. 008928 


.010 


.0132 


.0116 


.0122 


.0109375 


3 


.2291 


.259 


.2437 


.252 


.259 


.25 


32 


. 007950 


.009 


.0128 


.0108 


.0112 


.01015625 


4 


.2043 


.238 


. 2253 


.232 


.238 


. 234375 


33 


. 007080 


.008 


.0118 


.0100 


.0102 


. 009375 


5 


.1819 


.220 


.2070 


212 


.22 


.21875 


31 


. 006305 


007 


.0104 


.0092 


0095 


. 008.59375 


6 


.1620 


.203 


.1920 


'192 


^203 


.203125 


35 


.00.5615 


.005 


. 0095 


.0081 


0090 


.0078125 


7 


. 1443 


.180 


.1770 


176 


.18 


. 1875 


36 


. 005000 


00 1 


.0090 


0076 


. 0075 


.00703125 


8 


. 1285 


.165 


.1620 


.160 


.165 


. 171875 


37 


. 004453 




. 0085 


.0068 


0065 


. 006640625 


9 


. 1144 


.148 


. 1483 


144 


.148 


. 15625 


38 


. 003965 




.0080 


.0060 


.0057 


. 00625 


10 


.1019 


. 134 


.1350 


.128 


.134 


. 140625 


39 


. 003531 




. 0075 


. 0052 


.0050 




11 


. 09074 


.120 


. 1205 


.116 


.12 


.125 


40 


. 003145 




.0070 


.0018 


.0015 




12 


. 08081 


.109 


. 10.55 


.104 


.109 


. 109375 


41 


. 002800 






. 001 1 






13 


.07196 


.095 


.0915 


.092 


.095 


. 09375 


42 


. 002494 






. 0040 






14 


.06408 


.083 


.0800 


.080 


.083 


. 078125 


43 


.002221 






.0036 






15 


. 05707 


.072 


.0720 


,072 


.072 


. 0703125 


44 


. 001978 






.0032 






16 


0.5082 


.065 


0625 


064 


065 


0625 


45 


001761 






0028 






17 


. 04526 


.058 


.0540 


.056 


.058 


. 05625 


46 


. 001.568 






.0024 






18 


.04030 


.049 


.0475 


.048 


.049 


.05 


47 


.001397 






.0020 






19 


.03589 


.042 


.0410 


.040 


.040 


. 04375 


48 


.001244 






.0016 






20 


.03196 


.035 


. 0348 


.036 


.035 


.0375 


49 


.001018 






.0012 






21 


. 02846 


.032 


. 03175 


.032 


.0315 


. 034375 


50 


. 0009863 






.0010 






22 


. 02535 


.028 


.0286 


.028 


. 0295 


. 03125 

















Table 28-60. Useful Factors 



Igal. (U. S.){l 

1 gal (British) = 

1 cu. ft. = 

1 cu. ft. water at 60 deg. fahr. = 

1 gal. water at 60 deg. fahr. = 

1 cu. ft. water at 212 deg. fahr. = 

1 gal. water at 212 deg. fahr. = 

1 barrel water at 60 deg. fahr. 



1 inch mercury< ] 



1 lb. per sq. in. pressure 
Height of a column of water in feet X 0.434 
A column of water 1 sq. in. and 2J^ ft. high 



1 calorie 

1 kilogram 

Calories per kilo X 1.8 

1 kilowatt (1000 watts) 

1 horsepower 



3.97 B.t.u. 
= 2.2046 lb. 
= B.t.u. per lb. 
= 1.3405 hp. 
= 0.746 kw. 
lkilowatti=^6,9B.t'i.permin. 
\ = 3414 B.t.u. per hour 



231 cu. in. 

0.13368 cu. ft. 

277.274 cu. in. 

7.4805 gal. 

62.37 lb. 

8.34 lb. 

59.76 lb. 

7.99 lb. 

31)^ gal. = 262.7 1b. 

1}^ ft. or 13.6 in. water 

0.491 lb. per sq. in. 

2.304 ft. water at 60 deg. fahr. 

lb. pressure per sq. in. 

approximately 1 lb. 

f= 42.4 B.t.u. per min. 
= 2545 B.t.u. per hour 
= 33000 ft. lb. per min. 
1 boiler horsepower = 33479 B.t.u. per hour 
1 B.t.u. = 778 ft. lb. 
1 ft. lb. per sec. = 1.356 watts 



350 



Table 28-61. Standard Causes of Sheet Metal 





U. S. standard 


Birmingham or Stubs 


No. of 


Thickness, inches 


Weight per 


sq. ft, in lb. 


Thickness, inches 


Weight per sq. ft. in lb. 


No. of 


gauge 


















Fractions 


Decimals 


Iron 


steel 


Fractions 


Decimals 


Iron 

— ., „ 


Steel 


gauge 


7-0 


1-2 


. 5 


20.00 


20.4 


(Approx.) 




/ 


7-0 


6-0 


15-32 


. 46875 


18.75 


19.125 








6-0 


5-0 


7-16 


. 4375 


17.50 


17.85 










5-0 


4-0 


13-32 


. 40625 


16.25 


16.575 


29-64 


.454 


18.16 


18.52 


4-0 


3-0 


3-8 


.375 


15.00 


15.30 


27-61 


. 425 


17.00 


17.31 


3-0 


2-0 


11-32 


. 34375 


13.75 


14.025 


3-8 


.38 


15.20 


15.50 


2-0 





5-16 


.3125 


12.50 


12.75 


11-32 


.34 


13.60 


13.87 





1 


9-32 


. 28125 


11.25 


11.475 


19-64 


.3 


12.00 


12.24 


1 


2 


17-64 


. 265625 


10.625 


10.8375 


9-32 


.281 


1 1 36 


11. 59 


O 


3 


1-4 


.25 


10. 


10.2 


17-64 


.259 


10. 36 


10.. 57 


3 


4 


15-64 


. 23 1375 


9.375 


9.5625 


15-64 


.238 


9, 52 


9.71 


4 


5 


7-32 


. 21875 


8.75 


8.925 


7-32 


.22 


8.80 


8.98 


5 


6 


13-61 


. 203125 


8.125 


8.2875 


13-64 


^203 


8.12 


8.28 


6 


7 


3-16 


. 1875 


7.5 


7. 65 


3-16 


.18 


7.20 


7.31 


7 


8 


11-64 


.171875 


6 875 


7.0125 




.165 


6.60 


6.73 


« 


9 


5-32 


.15625 


6.25 


6.375 


5-32 


. 148 


5.92 


6.04 


9 


10 


9-61 


.140625 


5.625 


5.7375 


9-64 


. 134 


5.36 


5.47 


10 


11 


1-8 


.125 


5. 


5.1 


1-8 


.12 


J. 80 


4.90 


11 


12 


7-61 


. 109375 


4.375 


4.4625 


7-64 


.109 


1.36 


4.45 


12 


13 


3-32 


. 09375 


3.75 


3.825 


3-32 


.095 


3.80 


3 88 


13 


14. 


5-6 1 


. 078125 


3.125 


3.1875 


5-64 


.083 


3.32 


3.39 


11 


15 


9-128 


. 0703125 


2.8125 


2.86875 


.072 


2 88 


2.91 


15 


16 


1-16 


. 0625 


2.5 


2.55 


1-16 


.065 


2.60 


2.65 


16 


17 


9-160 


. 05625 


2.25 


2.295 




.0.58 


2.32 


2 37 


17 


18 


1-20 


.05 


2 


2.04 


3-61 


.049 


1 . 96 


2.00 


18 


19 


7-160 


. 04375 


1 . 75 


1.785 




. 042 


1.68 


1.71 


19 


20 


3-80 


. 0375 


1.50 


1 . 53 




. 035 


1 . to 


1. 13 


20 


21 


11-320 


.031375 


1.375 


1 . 4025 


1-32 


.032 


1.28 


1.31 


21 


22 


1-32 


.03125 


1.25 


1 . 275 




.028 


1.12 


1.14 


22 


23 


9-320 


. 028125 


1 . 125 


1 . 1 175 




.025 


1.00 


1.02 


23 


24 


1-40 


025 


1. 


1.02 




.022 


.88 


.90 


24 


25 


7-320 


. 021875 


.875 


.8925 




.02 


.80 


.82 


25 


26 


3-160 


. 01875 


.75 


.765 




.018 


.72 


.73 


26 


27 


11-610 


.0171875 


. 6875 


. 70125 


1-64 


.016 


.64 


.65 


27 


28 


1-64 


.015625 


.625 


. 6375 




.014 


.56 


.57 


28 


29 


9-640 


.0110625 


.5625 


. 57375 




.013 


.52 


..53 


29 


30 


1-80 


. 0125 


. 5 


.51 




.012 


.48 


.49 


30 


31 


7-640 


. 0109375 


.J 375 


. 44625 




.01 


.40 


.41 


31 


32 


13-1280 


.01015625 


. 10625 


.414375 




.009 


.36 


.37 


32 


33 


3-320 


. 009375 


.375 


. 3825 




.008 


.32 


.33 


33 


34 


11-1280 


. 00859375 


. 34375 


. 350625 




.007 


.28 


.29 


34 


35 


5-640 


. 0078125 


. 3125 


. 31875 




.005 


.20 


.20 


35 


36 


9-1280 


.00703125 


.28125 


. 286875 




.004 


.16 


.16 


36 


37 


17-2560 


. 00664062 


. 265625 


. 2709375 










37 


38 


1-160 


. 00625 


.25 


. 255 










38 



Table 28-62. Measures of Weight, Contents and Area 

Long Measure Square Measure Cubic Measure 

12 inches = 1 foot. 144 square inches = 1 square foot. 1728 cubic inches = 1 cubic foot. 

3 feet = 1 yard. 9 square feet = 1 square yard. 27 cubic feet = 1 cubic yard. 
5 J4 yards = 1 rod. 30 J^ square yards = 1 square rod. 

4 rods = 1 chain. 160 square rods = 1 acre. 
10 chains = 1 furlong. 640 acres = 1 square mile. 
8 furlongs = 1 mile. 

Liquid Measure 
4 gills = 1 pint. 31 H gallons = 1 barrel. 

2 pints = 1 quart. 2 barrels = 1 hogshead. 

4 quarts = 1 gallon. 

.351 



24.75 cubic feet = l perch. 
128 cubic feet = 1 cord. 



Avoirdupois Weight 
16 ounces = 1 pound. 
100 pounds = 1 hundredweight. 
20 cwt. = 1 ton. 



Table 28-63. Mensuration of Surfaces and Volumes 

Area of rectangle = length X breadth. 

Area of triangle = base X J^ perpendicular height. 

Diameter of circle = radius X 2. 

Circumference of circle = diameter X 3.1416. 

Area of circle = square of diameter X .7854. 

area of circle X number of degrees in arc. 

Area of sector of circle = 

360 

Area of surface of cylinder = circumference X length + area of two ends. 

To find the diameter of circle having given area: Divide the area by .7854, and extract the square root. 

To find the volume of a cylinder: Multiply the area of the section in square inches by the length in inches 

= the volume in cubic inches. Cubic inches -^ 1728 = volume in cubic feet. 
Surface of a sphere = square of diameter X 3.1416. 
Solidity of a sphere = cube of diameter X .5236. 
Side of an inscribed cube = radius of a sphere X 1.1547. 
Area of the base of a pyramid or cone, whether round square or triangular, multiplied by one-third of its 

height = the solidity. 
Diam. X .8862 = side of an equal square. 

Diam. X .7071 = side of an inscribed square. 5r = proportion of circumference to 

Radius X 6.2832 = circumference. diameter = 3.1415926. 

Circumference = 3.5446 X V area of circle. t2 = 9.8696044. 



Diameter = 1.1283 X Varea of circle. ^^ = 1-7724538. 

Length of arc = no. of degrees X .017453 radius. Log. t = 0.49715. 
Degrees in arc whose length equals radius = 57° 2958'. 1/^^ = 0.31831. 

Length of an arc of 1 deg. = radius X .017543. 1/360 = .002778. 

Length of an arc of 1 min. = radius X .0002909. 360/- = 114.59. 

Length of an arc of 1 sec. = radius X .0000048. 



Table 28-64. Electrical Units 

Volt — The unit of electrical motive force. Force required to send one ampere of current through one ohm 

of resistance. 
Ohm — Unit of resistance. The resistance offered to the passage of one ampere, when impelled by one volt. 
Ampere — Unit of current. The current which one volt can send through a resistance of one ohm. 
Coulomb — Unit of quantity. Quantity of current which, impelled by one volt, would pass through one ohm 

in one second. 
Farad — Unit of capacity. A conductor or condenser which will hold one coulomb under the pressure of one 

volt. 
Joule — Unit of work. The work done by one watt in one second. 
Watt — The unit of electrical energy, and is the product of ampere and volt. That is, one ampere of current 

flowing under a pressure of one volt gives one watt of energy. 
One electrical horsepower is equal to 746 watts. 
One kilowatt is equal to 1,000 watts. 
To find the watts consumed in a given electrical circuit, such as a pump motor, multiply the volts by the 

amperes. 
To find the volts, divide the watts by the amperes. 
To find the amperes, divide the watts by the volts. 

To find the electrical horsepower required by a motor, divide the watts of the motor by 746. 
To find the mechanical horsepower necessary to generate the required electrical horsepower, divide the latter 

by the efficiency of the generator. 
To find the amperes of a given circuit, of which the volts and ohms resistance are known, divide the volts by 

the ohms. 
To find the volts, when the amperes and ohms are known, multiply the amperes by the ohms. 
To find the resistance in ohms, when the volts and amperes are known, divide the volts by the amperes. 



352 



Table 28-71. Conversion of Fahrenheit and Centigrade Temperatures 



Formulae: fahr. = — cent. + 32 deg. cent. = ^ (fahr. ■ 



32 deg.) 



FAHR. 



CENT. 



10- 



"-10 



20—- 



30- 



32- 

Freezing 



40 ; 



50- 



60- 



70- 



80- 



90 = 



100= 



10 



20 



30 





FAHR 


CENT. 







- 40 










110= 


- 




'^Z- 






- 




120= 


1 50 




— 




— 






130 = 








= 


60 




140= 










ISO 






70 












160 — 


















170 — 


80 












180 — 


— 




— - 




190 - 


~ 90 




— - 






— 




200 ~- 



FAHR. 



210 : 



CENT. 



212- 

Boiling_ 



220 = 



100 



230 = 



240 = 



"110 



250 — 



260 = 



270 = 



120 



130 



280 = 



290 = 



300 = 



140 



FAHR 


CENT. 




- 150 


— 


- 


310 = 




= 


- 160 


320 = 


= 




^^n 




170 


:^ 


— 


340 — 




^ 






350— 


180 






360 — 


— 




370 — 


~190 






— 


380—. 








390 — - 


-200 






— ' 


. 400 — 



353 



General Index 



See also the following additional indexes: Tables, page 362; Webster Service 
Details, page 364; Webster Apparatus, page 366. 



Accumulator, water (see water accumulator) . . . 

Acid, tartaric, manufacture of 196 

Air, capacity of various sizes of pipes, (table) ... 69 

ducts, area of, for indirect radiators 54 

ducts, method of sizing 68 

ducts, sized by friction loss method 68-69 

ducts, sized by velocity method 68 

elimination, importance of, in dry kiln 

coils..... 181,186 

heat required to raise temperature of, 

(tables) 72, 73 

infiltration 31-33 

infiltration, B. t.u. required for, (table) 33 

infiltration, double-hung windows, (chart) .... 32 

infiltration, example of 33 

infiltration, experiment on 32 

pressure loss in ducts, (chart) 70 

properties of, (table) 331 

quantities required for ventilation, (table) .... 67 

recirculation of, in industrial plants 67 

removal devices, modulation system 162 

removal from coils in dry kilns 184 

resistance of elbows, (table) 71 

-separating tanks, description and dimensions 

of 264^266 

-separating tanks, discharge of returns through,144 
-separating tanks, plain, method of connecting 

returns from vacuum pump 144 

-separating tanks, water-control, method of 
connection to vacuum pump and to feed- 
water heater 145 

supply, cold, for schools 61 

supply for class rooms 61 

supply, proper 60 

velocities for fan system, public buildings. ... 67 
velocities for fan systems, various types of 

buildings, (table) 68 

Altitude, effect upon boiling point of water, 

(table) 332 

effect upon design of chimney 87 

Anchor points, allowable distance between 283 

Anthracite coal, heat values of, (tables) . . . 340, 341 
Apartment buildings, considerations leading to 
selection of type of heating system for. . .97, 109 

operating pressure 239 

Architectural features, effect upon selection of 

type of heating system 103 

Area, measures of, (table) 351 

Areas of circles, (table) 346-347 

Attachments for Sylpbon traps {see Trap attach- 
ments) 

Auditoriums, ventilation of 63 

Automatic pump and receiver, connections for 

discharge from vacuum pump 149 

Avoirdupois weights, (table) 351 

Bain marie (see Kitchen equipment) 

Ball check valves (see Modulation vent valves) 

Banquet haU, ventilation of 64 

Basement radiation, method of draining, modu- 
lation system 229, 232 

Belt driven vacuum pumps 143 

Bends, effect of, upon flow of steam through 

pipes, (table) 115 

Bituminous coal, heat values of, (table) 339-340 



Blanket warmers (see Hospital equipment) 

Blast heaters, connections for 225-227 

Blower sections, connections for 225-227 

Boiler feed pump and receiver, connections for 

discharge from vacuum pump 149 

feed pump controlled by air-separating tank, 

connections for , 149 

feeder, connections with double-control hydro- 
pneumatic tank and geared-type vacuum 

pump 147 

feeder, description and dimensions of 274 

rooms, size of 94, 108 

tubes, dimensions of, (table) 317 

Boilers, basis for rating 89 

cast iron type 106 

efficiency of 91 

high-pressure, as used in connection with 

vacuum systems 107 

method for cleaning 93 

modulation system connections for thermo- 
static and for time clock control of damper 

regulator 231 

modulation system connections for parallel 

operation 230 

necessity for withstanding corrosion in 106 

priming of 93, 105 

proportions of 90 

required firing periods for 93 

return tubular, dimensions of, (table) 330 

selection of proper type of 105-108 

water space of 90 

Boiling point of water at various altitudes, 

(table) 332 

Botanical gardens (see Greenhouses) 

Brass tubes, diameters and lengths of, (table) . . . 315 

British thermal unit, definition of 9 

Building, size and type of, for determining choice 
of heating system 97 

Calorific values of coal 340 

Candy, manufacture of 196 

Capacitv, air-carrying, of various sizes of pipes, 

(table) 69 

definition of 233 

Carpenter, Prof. R. C 112 

Ceilings, heat transmission factors for 30 

Centrigrade, conversion to fahrenheit scale .353 

Central station heat 107 

Check valves, special, for modulation systems, 

application details of 268, 269 

Chemical plants, exhaust ventilation for 65-66 

Chimney lining, dimensions of standard sizes of. . 75 

Chimneys, effect of altitude upon design of 87 

for house heating boilers 74 

capacity of, (table) 76-77 

limngs for, (table) 75 

proportioning of 74 

for power boilers 78 

procedure for proportioning 79 

Churches, considerations leading to selection of 

type of heating system for 100 

ventilation of ; 63 

Circles, circumferences and areas of, (table) . 346-347 

Clearance, vacuum pumps 139 

Cloth-drying machines, application of Webster 

apparatus to 190 



354 



General Index — Continued 



Cloth-drying machines, description of 190 

Coal, anthracite, heat values of, (table) . . . .340-341 

bituminous, heat values of, (table) 339-340 

calorific value of, (table) 340 

grate areas required for burning, (table) 92 

rates of combustion of, (table) 92 

Coals, classification of 339-340 

Coffee m-ns (see Kitchen equipment) 

Coils, continuous header type, in dry kilns 182 

design of, for lumber dry kilns 183 

drainage of 220-221 

pipe, Umit of length of 43 

pipe, surface in square feet of, (table) 56-57 

sectional header type in dry kilns 184 

vertical header type in dry kilns 185 

Cold air ducts, area of, for indirect radiation ... 54 

Combination gauges 267 

connections for 268 

Combination systems, vacuimi and modulation. 100 

Combustion rates for various coals, (table) 92 

Computation sheets for example of factory heat 

reqmrements 40-41 

Computation sheets for example of residence heat 

requirements 38-39 

Computations, for direct and indirect radia- 
tion 55-58 

for indirect radiation 53-54 

Condensation, losses in steam piping 113 

products of 12 

saving due to return to boilers. 13 

Condensed milk (see Condensories) 

Condensing engines, bleeding receiver of 175 

Condensories, appUcation of Webster system to . . 196 

Connections, details of, to indirect radiator 52 

offset, (table) .319 

Conserving system, description of 173 

typical layout of 173 

Conserving valves, description and dimensions of. 273 

illustration of . . . ^ 174 

Contents, measures of, (table) .351 

of round tanks, (table) 335 

Controllers, Hylo (see Hylo controllers) 
Cooking, steam appliances for (see Kitchen 

equipment) 
Copper tubes, diameters and lengths of, (table) . 315 
Costs of direct cast iron radiation, relative .... 51-52 

Critical velocities in radiator run-outs 132-134 

Critical velocity, definition of 132 

Cube roots of numbers, (table) 348-349 

Cubic measure, (table) 351 

Damper control for boilers 94 

Damper regulators, description and dimensions of .271 
method of control by thermostat and by time 

clock 231 

use in connection with conserving valve 175 

Dampers, air volume, at branch ducts 72 

Data required for design of steam heating sys- 
tems 15 

Decimal equivalents of fractions, (table). . .348-349 

equivalents of inches, (table) 344-345 

Densities of materials, (table) 342 

DifferentieJ-type return trap, description of . . . .155 
Differential pressures through traps and valves .238 

Direct radiation, definition of 11 

example of computation of 55, 58 

heat emission, (table) 45 

heat emission with varying room temperature. 47 
heat emission with varying steam pressure. . . 46 

relative costs of cast iron, (table) 51-52 

with exhaust systems 66 

Direct-indirect radiators, data for 55 



Direct-indirect radiators, description of 55 

Direct-indirect system of ventilation 60 

Dirt, effect of, on size of return mains 13 

Dirt strainers, description of 259 

dimensions of 260 

Disposal of condensation in vacuum systems . . . 171 

Doors, heat transmission factors for 28 

Double-control hydro-pneumatic tanks, descrip- 
tion and dimensions of 276-277 

used in connection with geared-type vacuum 

pump and boiler feeder 147 

Double-service vcdves 164 

description and dimensions of 252-254 

ratings of 237 

typical installation detail of 253 

Down-feed riser, definition of 12 

draining through radiator 220, 253 

Down-feed systems, modulation 163 

vacuum 167-168 

Draft, chimney, definition of 78 

intensity of, (formula) 79 

losses 80 

losses in boiler, (formula) 84 

losses in flues, (formula) 83 

losses in furnace, (formula) 84 

losses in stack, (formula) 81 

required for various fuels, (chart) 85 

Drag lifts 263 

Dry kibas 179 

causes of trouble in 181 

design of pipe coils for 183 

important features of design of 181 

plans showing use of continous-header coil in. 182 
plans showing use of sectional-header coil in . . 184 
plans showing use of vertical-header coil in. . . 185 

temperature with exhaust steam in 181 

temperature with live steam in 183 

use of exhaust steam in 181 

Dry returns, methods of connections for modu- 
lation systems 228-229 

modulation systems 162, 164 

Drying, cloth 190 

improper methods of lumber 179 

paper 192 

yarn 188 

Ducts, air-carrying, capacity of various sizes of, 

_ (table) 69 

air pressure loss in, (chart) 70 

area of, for indirect radiation 54 

comparison of friction in round and rectangular 71 

hot-air, with hot blast system 66 

method of sizing 68 

resistance of air in elbows of, (table) 71 

trunk line system, sized by friction loss 

method 68-69 

trunk hne system, sized by velocity method . . 68 
underground masonry, for schools 62 

Economizer, vapor, and suction strainer, des- 
cription and dimensions of 261-262 

Economy, feed-water heaters, (table) 301 

Economy of returning condensation to boiler ... 13 
Efficiency, increase in, for radiation with shield. 51 

decrease in, with enclosed radiators 50 

heating tests of return traps for 154 

Elbows, friction of water in, (table) 336 

resistance of air in, (table) 71 

Electrical units, definitions of 352 

Electric-driven vacuum pumps 137, 172 

for vacuum systems using low-pressure boilers. 173 
use of, in schools, churches, etc., for inter- 
mittent heating 100 



35S 



General Index — Continued 



Ekiclosed radiator, with grilles 49 

decreased efficiency of, (table) 50 

Enclosure for radiators 48 

Engine, horsepower of 329 

Evaporation, boiler, measurement of 313 

Expansion, joints, allowable distances between 

anchor points of 283 

joints, description and dimensions of ... . 278-282 

loops in risers 216 

of solids, lineal, (table) 344 

of wrought iron pipe, (table) 318 

Ebqposure and protective conditions 15 

Extra-heavy fittings, dimensions of, (table), 324^327 

flanges, dimensions of, (table) 324 

iron pipe, dimensions of, (table) 317 

Factories, removal of fumes or dust in 65 

Factors, basic, for heat transmission 25 

Factory, examples of computation sheet of heat 

requirements for 40-41 

plan showing heat requirements for 37 

Fans, sizes and arrangement of 72 

Feeder, boiler (see Boiler feeder) 

Feed-water heater, gravity return to 222 

economy of, (chart) 301 

steam-control type, typical connections to ... . 304 
water-control type, typical connections to ... . 303 

Webster, description of 302-313 

dimensions. Class EB 310 

dimensions. Class EBP 311 

dimensions. Class EF 313 

dimensions. Class EFP 312 

Fire protection for exposed water hydrants 195 

Fireplace 60 

Fittings, cast iron, screwed, dimensions of, 

(table) 319 

effect of, upon steam flow 115 

extra-heavy flanged, dimensionsof, (table) . 324^327 

extra-heavy flanged, rules for 324 

lift (see Lift fittings) 

standard flanged, dimensions of, (table) . . 320-323 

standard flanged, rules for 320 

Flanges, extra-heavy, dimensions of, (table) .... 324 

standard, dimensions of, (table) 320 

Float-type return trap, description of 154 

Floors, above cold space, heat transmission fac- 
tors for 29 

laid on ground, heat transmission factors for . . 30 

Flow of steam through pipes 110 

Flow of water, through elbows, (table) 336 

through pipes, (table) 337 

Flues, chimney (see Chimney flues) 

Food products, manufacture of 204 

Fractional equivalents of decimals, (table) . 348-349 

Friction, air in ducts, (chart) 70 

round and rectangular ducts, comparison of 

losses, (chart) 71 

steam in pipes. Ill 

water in elbows, (table) 336 

water in pipes, (table) 337 

Fuel saving by preheating feed water 301 

Fuels, draft required for different, (chart) 85 

Fumes, remov^ of 65 

Furnaces for steam boilers 90 

Gallon of water, weight at various temperatures 
of, (table) 335 

Gauges (see Combination gauges) 

combination (see Combination gauges) 

Hylo , 178 

sheet metal, (table) 351 

typical connections of 150 



Gauges, wire, comparison of, (table) 350 

Geared-type vacuum pump , . 146 

connections with boiler feeder and double-con- 
trol hydro-pneumatic tank 147 

with single-control hydro-pneumatic tank .... 146 
Generator, hot-water (see Hot-water generator) 

Glass, roof, heat transmission factors for 29 

Governor, vacuum pump (see Vacuum pump 
governor) 

typical connections for 151 

Grade of pipe, effect upon critical velocity of . . . 133 
Grate surfaces for various grades of coal, (table) . 92 

Grates for steam boilers 90 

Gravity, indirect radiation, definition of 11 

drips, hydraulic head for 119 

Grease traps, description of 257 

dimensions of 258 

method of connecting, for draining of oil sepa- 
rator 255 

Greenhouses, application of Webster systems to. 205 
GriUe enclosure for radiators 49 

Heads of water corresponding to pressures, 

(table) 333 

Heat absorbing capacity of materials 19 

absorption by stored materials 10 

content 9 

emission of direct radiation, (table) 45 

percentage of variation of, (chart) 44 

with varying room temperatures, (chart) .... 47 

with varying steam pressures, (chart) 46 

head 21 

location and character of source of 15 

loss required for air infiltration, (table) 33 

losses through monitors 24 

required to raise temperature of air, (tables) 72, 73 

requirements 10 

computation sheet for factory 40-41 

computation sheet for residence 38-39 

example of factory 36 

example of residence 35 

for stored materials 35 

method of calculating 34 

plan of factory 37 

where heating is not continuous 35 

specific, definition of 9 

stratification, iUustration of 23 

transmission, basic factors for 25 

transmission factors, ceilings 30 

doors 28 

floors above cold space 29 

floors laid on ground 30 

interior walls 25 

roof construction 28 

roof glass and skyUghts 29 

walls, brick 26 

walls, clapboard 25 

waUs, concrete faced with brick 26 

walls, concrete faced with stone 27 

walls, corrugated iron 26 

walls, hard stone or concrete 27 

waUs, hollow tile 27 

waUs, hollow tUe faced with brick 26 

walls, sandstone or limestone 27 

walls, stucco on studs 26 

windows 28 

windows above datum 28 

wood partitions 28 

transmission rates, fundamental conditions. . . 21 

transmitted through steam pipes 116 

units, definitions of 9 

values of various kinds of coal, (table). . .339-341 



356 



General Index — Continued 



Heater-meter, Webster-Lea, description of. 313-314 
Heaters, blast (see Blast heaters) 

feed-water (see also Feed-water heaters) 
feed-water, connections from water-control 

air-separating tank 145 

method of calculating size of 72 

Heating, initial 9 

Heating efficiency, tests of return traps for 1.54 

surface of pipe coils, (table) 56-57 

surface, boiler 90 

surface, character and location of 19 

surface, method of computing and selecting. . . 42 
systems, basic data required for the design 

of 15 

systems, hot blast 66 

Heavy-duty traps, connection for coils drained 

through one trap in lumber dry kilns 187 

high-differential type, application to drainage 

of vacuum pan 201 

high-differential type, description and dimen- 
sions of 249 

method of running return pipe in lumber dry 

kits 187 

sectional drawing of 225 

Series 19T, description of 247 

Series 19T, dimensions of 249 

Series 19T, ratings of 239 

use in lumber dry kilns 182, 186 

High-differential heavy-duty traps (see Heavy- 
duty high differential traps) 

High-duty vent trap 163 

application of 120 

High-pressure Sylphon traps, application for hos- 
pital equipment 202 

application for kitchen equipment 203 

application to hydrants to prevent freezing ... 195 

description and dimensions of 275 

typical installation for railroad switches 194 

Horsepower, boiler 89 

of an engine 329 

of return tubular boilers, (table) 330 

Hospital equipment, application of Webster sys- 
tems to 202 

Hospitals, considerations leading to choice of 

type of heating system for 107 

Hot air ducts, area of, for indirect radiation. ... 54 
Hot blast heating system for industrial plants . . 66 

Hot water generator, connections for 

222, 227, 229 
Hot water pattern radiation, connections for ... 43 
Hotels, considerations leading to selection of type 

of heating system for 106 

Humidity 59 

relative indoor 19 

HydrauUc head for gravity drips 119 

Hydro-pneumatic tanks, description and dimen- 
sions of 276-277 

discharge to. . . 147 

double-control, connections with geared-type 

vacuum pump and boiler feeder 147 

selection of size of 138, 142 

single-control, connections with geared-type 

vacuum pump , 146 

Hylo controllers 178 

controllers, dimensions of . . 272 

gauges 178 

systems, typical connections of special appa- 
ratus 177 

traps 178 

traps, dimensions of 272 

vacuum systems, description of 176 



Impurities, lack of, in distilled water 13 

in condensation 12 

Indirect radiation, connection for air supply of. 65 

definition of 11 

example of computation of 55-58 

formulae for computing 54 

method of computing 53-54 

methods of heating by 53 

with exhaust systems 66 

Indirect radiator, details of connection to 52 

Indirect stacks, connections for 225-227 

Indirect system of gravity ventilation 60 

Industrial plants, exhaust ventilation for 65 

hot blast systems for 66 

Infiltration, air 31 

B.t.u. reqijired for, (table) 33 

double-hung windows, (chart) 32 

example of 33 

Initial heating period 10 

Initial velocity of steam flow, (table) 110 

Inleakage of air to piping of vacuum system, 

effect of 122 

Inside temperature requirements, (table) 18 

Intermittent use of building, effect upon design 

of heating system 100 

Iron pipe, dimensions of, (table) 316-317 

J oints, expansion (see Expansion joints) 

Kettles, cooking (see Kitchen equipment) 

Kilns, lumber drying 179 

causes of trouble in 181 

construction of 180 

design of pipe coils for 183 

important features in design of 181 

plans showing use of continuous header coils in. 182 
plans showing use of sectional header coils in. 183 
plans showing use of vertical header coils in. , 185 

Kitchen, heating equipment for 106 

heating equipment, application of Webster 

systems to 203 

ventilating equipment for 64 

Laboratory tests of return traps 153 

Lift fittings, application for "step-up" Ufts 139 

Series 20, description of 263 

Series 20, dimensions of 264 

typical application of 263 

Lift pockets (see Lift fittings) 

Lifts, drag 263 

method of design for "step-up" 139 

Liquid measure, (table) 351 

Location of building, effect upon selection of 

design of heating system 101 

Lock-shield modulation valves 170 

Long measure, (table) 351 

Loss, friction, in round and rectangular ducts, 

(chart) 71 

Lubricator, force-feed 170 

sight-feed. 170 

sight-feed, typical connections of .151 

Lumber-drying, improper methods of .179 

kihis 179 

kilns, causes of trouble in 181 

kilns, important features in design of 181 

processes 179 

tests 180 

IVIachinery, heat-absorbing capacity of 19 

Mains, dripping, in vacuum system 167 

method of dripping 215 

ratings for vacuum and modulation return 128-129 



357 



General Index — Continued 



Mains, ratings for vacuum cuid modulation 

supply 128-129 

steam (see Risers) 

supply and return, definition of 12 

Material, densities of, (table) 342-343 

specific heats of, (table) 342 

tensile strength of, (table) 343 

weights of, (table) 341 

Measures of pressure, comparison of, (table) 334 

Mechanical indirect radiation, definition of 11 

Mechanical laboratory, illustration of 152 

Meeting rooms, ventilation of 64 

Mensuration of surfaces and volumes 352 

Meter-heater (see Heater-meter) 
MiUt condensories (see Condensories) 

Modulation system, advantages of 109 

basement, radiators for 162 

classes of structures for application of 96 

descriptions of 161 

down-feed 163 

dry return 162, 164 

elements of a 95 

layout of typical 160 

pressiu'e drop in 116 

proportioning of return mains for 121 

proportioning of steam mains for 121 

removal of air in 162 

return mains and risers in 162 

sizes of supply and return pipes, (table) . .128-129 

specification for typical 289 

supply mains and risers in 162 

taking steam from street, description of 164 

up-feed 163 

various types of 162 

wet return 163-164 

with boiler pressures up to 10-lb., description 

of 162 

with boiler pressures up to 50-lb., description 

of 163 

with pump and receiver 164 

Modulation valves, lock-shield type 170 

omission of 103 

Type W, description of 250 

dimensions of 252 

ratings of 237 

with chain attachment, description of 252 

with chain attachment, installation details of 251 

with extended stem 252 

vacuum systems 169 

Modulation vent traps 162 

description and dimensions of 268-270 

typical installation details of 268-269 

Modulation vent valves, application details 

of 268-271 

description and dimensions of 270-271 

Monitors, heat losses through 24 

Motor valves, attachments for 294 

Muffler oil separator 257 

Multiple-unit valves, attachments for 296 

National Dry Kibi Co 187 

Noise due to design of run-outs 134 

No. 7 Traps, description and dimensions of 246 

ratings of 238 

Offiee buildings, considerations leading to selec- 
tion of type of heating system for 97 

Offset connections, (table) 319 

Oil separator, allowable velocity through 255 

method of draining by means of grease trap . .255 
receiver and muffler 257 



Oil separator, Series 21, description of 254 

dimensions of 256 

ratings of 256 

Open return-line systems 95 

Operating pressure 239 

Painting, effect of, upon radiation 49 

Pans, vacuum (see Vacuum pans) 
Paper-drying machines, application of Webster 

apparatus to 191 

Partitions, wood, heat transmission factors for. . 28 
Performance of stationary steam plants, (table) . 334 

Piers, steamship, fire protection for. 195 

Pipe, air-carrying, capacity of various sizes of, 

(table) 69 

coils, continuous header type for dry kilns. . . .182 

limi t of length of 43 

sectional header type for dry kilns 184 

surface in square feet of, (table) 56-57 

vertical header type for dry kilns 185 

copper and brass (see Tubes) 

expansion of, (table) 318 

extra and double-extra strong, dimensions 

of, (table) 317 

friction of water in, (table) 337 

standard wrought iron, dimensions of, (table) . 316 

threads, standard, (table) 316 

Pipes, grading of mains, risers, and run-outs. ... 20 
sizes of supply and return for modulation and 

vacuum systems 128-129 

surface factors for 317 

Piping, steam, condensation losses in 113 

system, down-feed 20 

Piston speed in vacuum pumps 140 

Plain air separating-tank, description of 264 

dimensions of 266 

method of connecting discharge from vacuum 

pump 144 

selection of size 138, 142 

Plans, necessity for 18 

Pockets, lift (see Lift fittings) 

Power-driven reciprocating vacuum pumps 143 

Power load 165 

Powers of numbers, (table) 348-349 

Pressure, and weight, comparisons of, (table) . . . 333 

comparison of measures of, (table) 334 

corresponding to water-head, (table) 333 

differences 12 

drop in modulation systems 116 

in steam pipes 114 

in vacuum systems through return trap. 120-121 

to impart initial steam velocity 110 

schedule of 238 

drop through radiator trap in modulation sys- 
tems 117 

through return main 117 

through vent trap 117 

through vent valve 116 

in pipes, calculation of air. 69 

loss in ducts, (chart) 70 

operating 239 

-reducing valve, connections for 216 

connections to water accumulator 267 

vacuum system 166 

regulator (see Pressure-reducing valve) 

Priming of boilers 105 

Properties of air, (table) 331 

Properties of saturated steam, (table) 328-329 

Public buildings, allowable air velocities for fan 

systems in 67 

considerations leading to selection of type of 
heating system for 98 



.358 



General Index — Continued 



Public buildings, operating pressure in 239 

Pump £ind receiver, conditions requiring use 

of.... 99 

connections for discharge from vacuum pump 

to 119 

disciiarge of returns from vacuum pump to. . . 148 

use of in a modulation system 161 

Pump governor, vacuum, description and dimen- 
sions of 260 

Pump, vacuum, sizing, (table) 138 

Radiation, cast iron wall, in factory 12, 44 

direct, definition of 11 

example of computation of 55, 58 

heat emission, (table) 45 

heat emission with varying room tempera- 

tiu-es, (chart) 47 

heat emission with varying steam pressures . 46 
direct and indirect, with e.xhaust systems .... 66 

effect of painting on 49 

hot water pattern, connections of 43 

indirect, definition of 11 

formula for computing 54 

methods of computing 53-54 

methods of heating by 53 

hmit of length of wall 43 

method of computing and selecting 42 

percentage variation in heat emission, (chart) . 44 
relative costs of cast iron direct, (table) . . . .51-52 

square feet of, definition of 12 

Radiators, connections on vacuum system 169 

direct-indirect, data for 55 

direct-indirect, description of 55 

enclosed, decreased efficiency of, (table) . . , 50-51 

enclosed with grilles 49 

enclosures 48 

indirect, details of connection to 52 

run-outs, critical velocity in 132-134 

transmission rate, variation of 11 

traps {see also Return traps) 

traps, pressure drop through 117 

with shield, increased efficiency of, (table) .... 51 
valves {see Modulation valves) 
Railroad switches, method of prevention of 

freezing 194 

Railroad terminals 194-195 

Rating, definition of 233 

Ratings, angle valves, (inlet) 237 

double-service valves 237 

heavy-duty traps 238-239 

modulation valves 234-237 

modulation vent traps 240 

modulation vent valves 240 

No. 7 traps 237-238 

supply and return mains 128-129 

supply valves 237 

Sylphon traps 237-238 

Type W modulation valves 237 

Receiver and muffler oil separators 257 

Receiving tanks, description and dimensions 

of 264-266 

plain, method of connecting returns from 

vacuum pump to 144 

selection of size of 138, 142 

water-control, method of connection with 

vacuum pump and feed-water heater 145 

Reciprocating vacuum pumps, power-driven. . . . 143 

proportions of 138 

Recirculation of air in industrial plants 67 

Reducing valves {see Pressure-reducing valves) 
Re-evaporation 261 



Re-evaporation, chart . ; 157 

of discharge from return traps 156 

Registers, area of, for indirect radiators 54 

Regulators, damper {see Damper regulators) 
pressure (see Pressure-reducing valves) 
vacuum {see Vacuum pump governors) 

Relative humidity 59 

Residences, boiler pressure for 239 

considerations leading to selection of type of 

heating system for 97, 108 

example of heat requirements for, computa- 
tion sheet 38-39 

heat requirements for, plan showing 36 

Resistance, of coils and air washers 72 

of fittings to steam flow 113-115 

of 90° elbows, (table) 71 

of pipes to air flow, calculation of 69 

Return mains, definition of 12 

for modulation systems, proportions of . . . .121 

for vacuum systems, proportions of 122 

function of 12 

ratings of, (table) 128-129 

sizing of 141 

piping, location of 20 

modulation systems 162-164 

tanks {see also Tanks) 

uses in vacuum system 171 

traps, differential type, description of 155 

float type, description of 154 

method of running return pipe to 187 

No. 7, description and dimensions of 246 

No. 7, ratings of 237-238 

objects of tests in laboratory 153 

outboard type 156 

pressure drop allowable through 117 

requirements for perfect operation of 241 

selection of size and type of 238 

Sylphon, description of 242-245 

Sylphon, dimensions of . . 245 

Sylphon, ratings of 237-238 

testing 153 

tests for heating efficiency of 154 

thermostatic type, description of 155 

use of, for air removal 186 

use of, in lumber dry kilns 182, 18 1-186 

tubular boilers, dimensions of, (table) 330 

Returns, dry, methods of connections for modu- 
lation systems 228-229 

flashing of 122 

intermittent 105 

methods of cooling 122 

Risers, down-feed, draining through radiator 220,253 

drainage of 216-219, 224 

dripping, vacuum system 167 

method of providing for expansion of 216 

modulation systems, methods of draining . 228-229 
return, proportions of, for vacuum systems. . .122 

up-feed and down-feed, definition of 12 

used as heating surface 219 

Roof construction, heat transmission factors 

for 28 

Roof glass, heat transmission factors for. 29 

Roots of numbers, (table) 348-349 

Rotating vacuum pumps 137 

Round tanks, contents of, (table) 335 

Run-outs, above floor 219 

critical velocity in 132-134 

in floor 218 

sizing of 135-136 

under floor 219 

vacuum svstems 170 



359 



General Index — Continued 



Salt, manufacture of 196 

Saturated steam, properties of, (table) 328-329 

School rooms, arrangement of diffusers and 

direct radiation for 62 

Schools, considerations leading to selection of 

type of heating system for 98, 108 

operating pressures for 239 

ventilating system for 61 

Selection of proper type of steam heating system, 

fundamental considerations leading to 97 

Separating tanks (see Air-separating tanks) 

Separators, oil, allowable velocity through 255 

method of draining 255 

receiver and muffler type of 257 

Series 21, description of 254 

dimensions of 256 

ratings of 256 

Separators, steam. Series 21, description and di- 
mensions of 283-285 

Service details (see separate index) 

Sheet metal gauges, (table) 351 

Shield, radiator, increase in efficiency due to. . . . 51 
Single-control hydro-pneumatic tanks, con- 
nections to geared-type vacuum pump 146 

description and dimensions of 276-277 

Sizing run-outs for various grades and quan- 
tities 135-136 

Skin-friction 114 

Skyhghts, heat transmission factors for 29 

Slasher equipment, typical application of 189 

Slashers, equipment for 188 

Slope of pipe, effect of upon critical velocity. . . . 133 

Specific heat, definition of 9 

Specific heats of materials, (table) 342-343 

Specifications, typical, for modulation system. . .289 

for vacuum system 286 

Spitzglass, J. M .112 

Square feet of radiation, definition of 12 

Square measure, (table) 351 

Square roots of numbers, (table) 348-349 

Stacks (see Chimneys) 

indirect, connections for 225-227 

Standard fittings, dimensions of, (table) .... 320-323 

Standard flanges, dimensions of, (table) 320 

Standard iron pipe, dimensions of, (table) 316 

Stand-pipes, air-separating 144 

Stationary steam plants, performance of, (table) . 334 

Steam, (tables) 328-329 

-control tanks, control of boiler feed pump, 

connections 149 

-control tanks, description of 265 

dimensions of 266 

-driven reciprocating vacuum pumps, propor- 
tions of 138 

-driven vacuum pumps, typical connections 

to .' 150, 166 

end, vacuum pump, proportioning of 143 

exhaust, use of, in dry kilns 181 

flow, effect of pipe fittings on 115 

flow through standard pipes 112-115 

heating systems, types of 95 

mains, drainage of 215 

mains, dripping, vacuum systems 167 

plants, stationary, performance of, (table) 334 

requirements for tempering air 61 

saturated, properties of, (table) 328-329 

separators, ratings of 285 

separators. Series 21, description and dimen- 
sions of .283-285 

supply, sources of, effect upon selection of 

type of heating system 103 

supply, vacuum systems, source of 165 



Steamship piers, fire protection for 195 

Sterilizers (see also Hospital equipment) 107 

Storage of returns 142 

Store buildings, considerations leading to selec- 
tion of type of heating system for 97 

Strainers, dirt, description of 259 

dimensions of 260 

suction, and vapor economizer, description and 

dimensions of 261-262 

description of 258 

dimensions of 259 

selection of size of 138, 141 

typical connections to 150 

use of, on lumber dry kiln coils 186 

Stratification, factors for 24 

formula for temperature due to 25 

illustration of 23 

Street steam, supply 107 

system, method of cooling returns 222 

system, vacuum 173 

Strength, tensile, of materials, (table) 343 

Suction strainers 171 

and vapor economizer, dimensions and de- 
scription of 261-262 

description of 258 

dimensions of 259 

selection of size of 138, 141 

ty piccd connections to 150 

Sugar, manufacture of 196 

Supply mains, and risers for modulation sys- 
tems 162 

definition of 12 

for modulation systems, proportions of 121 

for vacuum systems, proportions of 122 

ratings of, (table) 128-129 

Supply pipes, location of 20 

Supply risers (see also Risers) 

drainage by means of heavy-duty traps 223 

Supply valves (see also Modulation valves) 

ratings of 237 

selection of size and type of 239 

Surface factors for pipes, (table) 317 

Surfaces and volumes, mensuration of 352 

Switches, railroad, method of prevention of 

freezing 194 

Sylphon attachments (see Trap attachments) . 

Sylphon traps, description of 242-245 

dimensions of 245 

ratings of 237-238 

Tanks, air-separating, description and dimen- 
sions of _ 264-266 

air-separating, selection of size of 138, 141 

hydro-pneumatic, description and dimensions 

of 276-277 

selection of .size of 138, 142 

single control, connections with geared-type 

vacuum pump 146 

plain air-separating, method of connecting re- 
turns from 144 

plain, selection of size of 138, 142 

round, contents of, (table) 335 

steam-control, connections to boiler feed pump 

and vacuum pump 149 

selection of size of 138, 142 

water-control, method of connection with 
vacuum pump and to feed-water heater. .145 

selection of size of , 138, 142 

Temperature, at ceiling, air mechanicaUy agitated 24 

at ceiling, high rooms 23 

average of high rooms 23 

comfortable 59 



360 



General Index — Continued 



Temperature, daily maximum and minimum in 

New York 16-17 

difference, factors for, (chart) 22 

due to stratification, (formulae) 25 

for various rooms, (table) 18 

increase in high buildings 23 

requirements, inside, (table) 18 

Temperatures, lowest recorded, (chart) 14 

Tensile strength of materials, (table) 343 

Terminals, railroad 194-195 

Tests of lumber drying 180 

Tests of retinn traps 153 

Theatre ventilation 63 

Thermometer scales, conversion of 353 

Thermostatic-type return trap, description of. . . 155 
Thermostatic valve No. 4, trap attachments for. 294 

Threads, pipe, standards, (table) 316 

Topography 15 

Transmission of heat through pipe 113 

Transmission rate of radiators, variation of 11 

Trap attachments 293 

for motor valves 294 

for multiple-unit valves 296 

for thermo-valves 294 

for various types of valves 297 

for water-seal motors 294 

for water-seal traps 295 

Traps (see also Return traps) 

grease and oil, description and dimensions 

of 257-258 

method of connecting for draining oil sepa- 
rator 255 

Traps, heavy-duty, high differential 249 

heavy-duty, beries 19T, description of 247 

dimensions of 249 

ratings of 239 

high-pressure Sylphon (see High-pressure 

Sylphon traps) 
Hylo (see Hylo traps) 

modulation vent (see Modulation vent traps) 
proper location of thermostatic type on lumber 

dry kiln coils 186 

proper type for lumber dry kilns 184 

return, testing 153 

water-seal, attachments for 295 

Tubes, boiler, dimensions of, (table) 317 

brass and copper, diameters and weights of, 

(table) 315 

Tubular boilers, dimensions of, (table) 330 

United States Weather Bureau, daily tempera- 
tures, 1916 to 1920 16-17 

lowest temperatures recorded, (chart) 14 

Units, heat, definitions of 9 

Up-feed risers, definition of 12 

Up-feed systems, modulation 163 

vacuum 167-168 

Vacuum governors, sizing of 138, 143 

typical connections of 151 

pans, application of apparatus 201 

drainage of 196 

pumps. . , 137, 170 

belt-driven 143 

discharging to automatic pump and receiver, 

connections for 149 

electric-driven 137, 172 

geared-type 143 

governor 170 

governor, description and dimensions of . . . .260 

reciprocating, proportions of 138 

rotating 137 



Vacuum governor, sizing of, (table) 138 

steam-driven, typical connections of.. .150, 166 

steam-ends, proportioning of 143 

water-and-air ends, proportioning of 140 

regulators (see Vacuum pump governors) 

systems, advantages of 109 

classes of structures for application of 96 

degree of vacuum for 122 

descriptions of 165 

different types of 165 

disposal of condensation in 171 

down-feed 167-168 

dripping mains and risers for 167 

elements of 96 

Hylo, description of 176 

pressure drop through traps in 121 

proportions of mains and risers for 122 

pumps for 170 

radiator connections for 169 

radiator supply valves for 169 

requirements of 12 

run-outs for 170 

sizes of supply and return mains, (table) 127-129 

sources of steam supply for 165 

typical layout of 166 

typical problem of sizing pipe for 123 

typical specification for 286 

up-feed 167-168 

using street steam 173 

ventilation problems with 172 

with boiler pressines from 15 to 50-lb 172 

with low pressure boilers 173 

with power boilers, description of 165 

Valves (see also Modulation valves) 
conserving (see Conserving valves) 
effect of, upon flow of steam through pipes. . .115 
modulation vent (see Modulation vent valves) 

radiator outlet, attachments for 297 

Vapor economizer and suction strainer, descrip- 
tion and dimensions of 261 

Velocity, air for fan systems in pubfic buildings. 67 
air for fan systems in various types of buildings 68 

allowable through oil separators 256 

critical, in radiator run-outs 132-134 

-head factors, (table) 348-349 

initial, of steam flow, (table) 110 

Vent traps, high-duty, appHcation of 120 

location of 120 

modulation (see Modulation vent traps) 

pressure drop through 117 

valves, modulation (see Modulation vent 
valves) 

pressure drop through 117 

Ventilation, apparatus, selection of 72 

banquet halls and meeting rooms 64 

churches 63 

direct-indirect system 60 

exhaust, for industrial plants 65 

gravity indirect system 60 

kitchens 64 

methods 60 

problems 59 

problems in design of vacuum system. ...... .172 

schools 61-62 

theatres and auditoriums 63 

Vento radiation, connections for draining .. 225-227 
Volumes and surfaces, mensuration of 352 

\Af Type modulation valves, description of 250 

dimensions of 252 

ratings of 237 

WaU radiation, cast iron, in factory 42, 44 



361 



General Index — Continued 



Wall radiation, methods of applying 102, 104 

illustration of application in factory 44 

limit of length of 43 

Walls, heat transmission factors for, brick 26 

clapboard 25 

concrete faced with brick or stone 26-27 

corrugated iron 26 

hard stone or concrete 27 

hollow tile 27 

hollow tile faced with brick 26 

interior 25 

sandstone or Umestone 27 

stucco on studs 26 

Warming-up period 10 

Warp drying 190 

Water accumulator, description and dimensions 

of 267 

typical connections to conserving valve 173 

typical connections to pressure-reducing 

valve 267 

-and-air end, vacuum pump, proportioning of. 140 

benefits of returning to boiler 13 

-control tank, description of 264 

dimensions of 266 

method of connection to vacuum pump and 
feed-water heater 145 



Water-control tank, selection of size of . . . . 138, 142 

conversion factors of, (table) 338 

cost at stated rates, (table) 338 

-seal motors, attachments for 294 

-seal traps, attachments for 295 

weight and volume at various temperatures, 
(table) 332 

Weather Bureau, United States, lowest tempera- 
tures recorded, (chart) 14 

Webster apparatus (see separate index) 

systems of steam heating, descriptions of 161 

Weight, cuid pressure, comparison of, (table) . . .333 

measures of, (table) 351 

of 1 gallon of water at various temperatures, 
(table) 335 

Wet-returns, modulation systems 162, 164 

Windows, double-hung, air infiltration through, 

(chart) 32 

heat transmission factors for 28 

heat transmission factors for, above datum. ... 28 

Wire gauges, comparison of, (table) 350 

Wood partitions, heat transmission factors for . . 28 

Yarns, sizing and drying of 188 

Y.M.C.A. buildings, considerations leading to 
selection of type of heating system for 106 



Tables 



Air, heat required to raise temperature of.. . .72-73 

infiltration, B.t.u. required for 33 

pressure loss in ducts, chart of 70 

properties of 331 

quantities required for ventilation 67 

resistance of elbows 71 

velocities for fan systems in public buildings. . 67 
velocities for fan systems in various types of 

buildings 68 

Altitude, effect of, upon boiUng point of water. . 332 

Anthracite coal, heat values of 340-341 

Area, measures of 351 

Areas of circles 346-347 

Avoirdupois weight 351 

Bends, effect upon steam flow through pipes. . .115 

Bituminous coal, heat values of 339-340 

Boiler tubes, dimensions of 317 

Boilers, return tubular, dimensions of 330 

Boiling point of water at various altitudes 332 

Brass tubes, diameters and lengths of 315 

Calorific values of coal 340 

Ceihngs, heat transmission factors for 30 

Centigrade, conversion to fahrenheit scale 353 

Chimney lining, dimensions of standard sizes. . . 75 

Circles, circuniferences and areas of 346-347 

Coal, anthracite, heat values of 340-341 

bituminous, heat values of 339-340 

calorific value of 340 

classification of 339-340 

grate areas required for burning 92 

rates of combustion of 92 

Coils, pipe, surface in square feet 56-57 

Combustion rates for various coals 92 

Connections, offset 319 

Contents, measures of 351 

of round tanks 335 

Copper tubes, diameters and lengths of 315 

Cost of direct cast iron radiation, relative 52 

Cube roots of numbers 318-349 



Cubic measure 351 

Decimal equivalents of fractions 348-349 

of inches 344-345 

Densities of materials 342 

Differential pressures through traps and valves . 238 

Direct radiation, heat emission 45 

heat emission with varying steam pressures .... 46 

relative costs of cast iron 52 

Direct-indirect radiators, data for 55 

Doors, heat transmission factors for 28 

Ducts, air-carrying, capacity of various sizes of. 69 

air pressure loss in, chart of 70 

resistance of air in elbows of 71 

Economy of feed-water heaters 301 

Efficiency, increase in radiation with shield 51 

decrease of, in enclosed radiators 50 

Elbows, friction of water in 336 

resi-stance of air fine 71 , 

Electrical units, definitions of 352 

Engine, horse power of 329 

Expansion, wrought iron pipe 318 

solids, fineal 344 

Extra-heavy fittings, dimensions of 324-327 

flanges, dimensions of 324 

iron pipe, dimensions of 317 

Factors, basic, for heat transmission 25 

Feed-water heaters, economy chart for 301 

Fittings, effect of, upon steam flow 115 

extra-heavy flanged, dimensions of ..... . 324^327 

extra-heavy flanged, rules for 324 

screwed cast iron, dimensions of 319 

standard flanged, dimensions of 320-323 

standard flanged, rules for 320 

Flanges, extra-heavy, dimensions of 324 

standard, dimensions of 320 

Floors, above cold space, heat transmission 

factors for 29 

laid on ground, heat transmission factors for. 30 

362 



Index of Tables — Continued 



Flow of water, through elbows 336 

through pipes 337 

Fractional equivalents of decimals 348-349 

Friction, air in ducts, chart of 70 

loss, comparison between round and rectan- 
gular ducts 71 

water in elbows 336 

water in pipes 337 

Gallon of water, weight at various tempera- 
tures 335 

Gauges, sheet metal 351 

wire, comparison of 350 

Glass, roof, heat transmission factors for 29 

Grate surfaces for various grades of coal 92 

Heads of water corresponding to pressures 333 

Heat, emission of direct radiation with varying 

room temperatures 47 

emission of direct radiation with varying 

steam pressures 46 

emission of radiation, percentage variation .... 44 

required to raise temperature of air 72-73 

transmission, basic factors for 25 

transmitted through steam pipes 114, 116 

values of various kinds of coal 339-340 

Horsepower, of an engine, 329 

of return tubular boilers 330 

Hydro-pneumatic tanks, selection of size . . .138, 142 

I nfiltration, B.t.u. required for 33 

chart for double-hung windows 32 

Inside temperature requirements 18 

Iron pipe, dimensions of 316-317 

Liquid measure 351 

Long measure 351 

Loss, friction, in round and rectangular ducts. . . 71 

IVIains, ratings for return 128-129 

ratings for supply 128-129 

Materials, densities of 342 

specific heats of 342-343 

tensile strength of 343 

weights of 341 

Measures of pressure, comparison of 334 

Mensuration of surfaces and volumes 352 

Offset connections 319 

Partitions, wood, heat transmission factors for . 28 

Performance of stationary steam plants 334 

Pipe, air-carrying, capacity of various sizes of. . . 69 

coils, surface in square feet 56-57 

copper and brass {see Tubes) 

expansion of 318 

extra and double-extra strong, dimensions. . . .317 

friction of water in 337 

sizes of supply and return 128-129 

standard wrought iron, dimensions of 316 

■ surface factors for 317 

threads, standard 316 

Plain air-separating tanks, selection of size. 138, 142 

Powers of numbers 348-349 

Pressure, and weight, comparison of 333 

comparison of measures of 334 

corresponding to water heads 333 

drop to impart initial steam velocity 110 

drops, schedule of 238 

loss in ducts, chart of 70 

Properties of air 331 



Properties of saturated steam 328-329 

Public buildings, allowable air velocities in fan 

systems 67 

Pumps, vacuum, sizing of 138 

Radiation, direct, heat emission 45 

direct, heat emission with varying room tem- 
peratures 47 

direct, heat emission with varying steam 

pressures 46 

percentage variation in heat emission 44 

relative costs of cast iron direct 52 

Radiators, direct-indirect, data for 55 

enclosed, decreased efficiency of 50 

with shield, increased efficiency of 51 

Ratings of supply and return mains 128-129 

Receiving taiiks, selection of size of 138, 142 

Re-evaporation chart 157 

Resistance, of 90° elbows 71 

to steam flow of fittings 115 

Return mains, modulation systems, proportions 

of 121 

ratings of 128-129 

Return tubular boilers, dimensions of 330 

Roof glass, heat transmission factors for 29 

Roots of numbers 348-349 

Round tanks, contents of 335 

Run-outs, sizing of 135-136 

Saturated steam, properties of 328-329 

Sheet metal gauges 351 

Shields, radiator, increase in efficiency due to. . . 51 
Sizing run-outs for various grades and quan- 
tities 135-136 

Skylights, heat transmission factors for 29 

Specific heats of materials 342-343 

Square measure 351 

Square roots of numbers 348-349 

Standard fittings, dimensions of 320-323 

Standard iron pipe, dimensions of 316 

Stationary steam plants, economic performance 

of 334 

Steam-driven reciprocating vacuum pump, pro- 
portions of 138 

Steam, flow, effect of pipe fittings on 115 

flow through standard pipes 114-115 

plants, economic performance of 334 

properties of 328-329 

saturated, properties of 328-329 

Strainer, suction, selection of size of 138, 141 

Strength, tensile, of materials 343 

Suction strainer, selection of size of 138, 141 

Supply mains, for modulation systems, propor- 
tions of 121 

ratings of 128-129 

Surface factors for pipe 317 

Surfaces emd volumes, mensuration of 352 

Tanks, air-separating, selection of size of. .138, 141 

hydro-pneumatic, selection of size of 138, 142 

plain, selection of size of 138, 142 

round, contents of 335 

steam-control, selection of size of 138, 142 

water-control, selection of size of 138, 142 

Temperature difi'erence, chart of factors for .... 22 

Temperature for various rooms 18 

Temperature requirements, inside 18 

Tensile strength of materials 343 

Thermometer scales, conversion of 353 

Threads, pipe, standard 316 

Transmission of heat through pipe 114, 116 

Tubes, boiler, dimensions of 317 



363 



Index of Tables — Continued 



Tubes, copper, brass, diameters and weights of. . 315 
Tubular boilers, dimensions of 330 

Vacuum governors, sizing of 138, 143 

Vacuum pumps, reciprocating, proportions of. . .138 

sizing of 138 

Valves, effect of, upon flow of steam through pipes 115 
Velocities of air for fan systems in public build- 
ings 67 

Velocity-head factors 348-349 

Volumes and surfaces, mensuration of 352 

\A/alls, heat transmission factors for, brick 26 

clapboard 25 

concrete faced with brick 26 

concrete faced with stone 72 



Walls, corrugated iron 26 

hard stone or concrete 27 

hollow tile 27 

hollow tile faced with brick 26 

interior 25 

sandstone or Umestone 27 

stucco on studs 26 

Water, conversion factors 338 

cost at stated rates 338 

weight and volume at various temperatures . . 332 
Water-control tanks, selection of size of.. . .138, 142 

Weight, and pressure, comparison of 333 

measures of 351 

of one gallon of water at various temperatures. 335 

Windows, heat transmission factors for 28 

Wire gauges, comparison of 350 

Wood, partitions, heat transmission factors for. . 28 



Webster Service Details 



Accumulator, water (see Water accumulator) 
Air-separating tank, plain, method of connecting 

returns from vacuum pump 144 

water-control, method of connecting to vac- 
uum pump and to feed-water heater 145 

Automatic pump and receiver, connections for 
discharge from vacuum pump 149 

Bain marie (see Kitchen equipment) 
Ball check valves (see Modulation vent valves) 
Basement radiation, method of draining, modu- 
lation system 229, 232 

Blanket warmers (see Hospital equipment) 

Blast heaters, connections for 225-227 

Blower sections, connections for 225-227 

Boiler-feed pump, and receiver, connections for 

discharge from vacuum pump 149 

controlled by air-separating tank, connections 

for 149 

Boiler feeder coimections with double-control 
hydro-pneumatic tank and geared-type vac- 
uum pump 147 

Boilers, modulation system, connections for ther- 
mostatic and for time clock control of 

damper regulator 231 

modulation system, method of connection for 
parallel operation 230 

Cloth-drying machines, appUcation of Webster 
apparatus to 190 

Coffee Urns (see Kitchen equipment) 

Coils, design of, for lumber kilns 183 

drainage of 220-221 

Combinatibn gauges, connections for 268 

Condensed milk (see Condensories) 

Condensories, appUcation of Webster system 
to.. 196 

Conserving system, typical layout of 173 

Controllers, Hylo (see Hylo controllers) 

Cooking, steam appliances for (see Kitchen 
equipment) 

Damper regulators, methods of control by 
thermostat and by time clock 231 

Double-control hydro-pneumatic tank, used in 
connection with geared-type vacuum pump 
and boiler feeder 147 

Double-service valves, typical installation, de- 
tail... . _. 253 

Down-feed risers, draining through radiator. 220, 253 



Dry kilns, design of pipe coils for 183 

plans showing use of continuous header coil 

for 182 

plans showing use of sectional header coil for. .184 
plans showing use of vertical header coil for . . 185 
Dry returns, methods of connections for modu- 
lation systems 228-229 

Expansion loops in risers 216 

Feeder, boiler (see Boiler feeder) 

Feed-water heater, gravity return to 222 

typical connections, steam-control type 304 

typical connections, water-control type 303 

Fire protection for exposed water hydrants 195 

Fittings, lift (see Lift fittings) 

Gauges (see Combination gauges) 
cornbination (see Combination gauges) 

typical connections for 150 

Geared-type vacuum pump, connections with 
boiler feeder and double-control hydro- 
pneumatic tank 147 

connections with single-control hydro-pneu- 
matic tank 146 

Generator, hot water (see Hot water generator) 
Governor, vacuum pump (see Vacuum pump 
governor) 

vacuum pump, typical connections of 151 

Grease trap, method of connecting for draining 
of oil separator 255 

Heater, blast (see Blast heater) 
feed-water (see also Feed-water heater) 
feed-water, connections from water-controlled 

air-separating tank 145 

Heavy-duty trap, connections for coils drained 

through one trap in lumber kilns 187 

sectional drawing of 225 

High-differential heavy-duty trap, application to 

drainage of vacuum pans 201 

High-pressure Sylphon trap, appUcation for hos- 
pital equipment 202 

appUcation for kitchen equipment 203 

appUcation to hydrants to prevent freezing. . .195 

typical installation for railroad switches 194 

Hospital equipment, appUcation of Webster 

system to 202 

Hot water generator, connections for. . 222, 227, 229 

364 



Index of Webster Service Details — Continued 



Hydro-pneumatic tank, double-control, con- 
nections with geared-type vacuum pump 

and boiler feeder 147 

single-control, connections with geared-type 
vacuum pump 146 

Hylo systems, typical connections of special 
apparatus 177 

Indirect radiation, connection for air supply. . . 65 

Indirect radiator, details of connection to 52 

Indirect stack, connections for 225-227 

J oint, expansion (see Expansion joint) 

Kettle, cooking (see Kitchen equipment) 

Kilns, design of pipe coils for 183 

plans showing use of continuous header coils. .182 
plans showing use of sectional header coil. . . .184 
plans showing use of vertical header coil for. . 185 

Kitchen equipment, apphcation of Webster sys- 
tem to 203 

Kitchen, ventilating equipment for 64 

Lift fittings, application for "step-up" Ufts. ..139 
Lift pockets (see Lift fittings) 

lifts, method of design for "step-up" 139 

Lubricators, sight, typical connections of 151 

Mains, method of dripping 215 

steam (see Risers) 
Milk condensories (see Condensories) 

Modulation system, typical layout 160 

system, valves with chain attachment, in- 

staEation details 251 

vent traps, typical installation details 268-269 

vent valves, application details 268-271 

Oil separators, method of draining by means of 
grease trap 255 

Pans, vacuum (see Vacuum pans) 

Paper-drying machine, application of Webster 
apparatus to 191 

Pier, steamship, fire protection for 195 

Pipe coils, drainage of 220-221 

use of continuous header type in dry kilns.. . . 182 

use of sectional header type in dry kilns 184 

use of vertical header type in dry kilns 185 

Plain air-separating tanks, method of connecting 
discharge from vacuum pump 144 

Pockets, hft (see Lift fittings) 

Pressme-reducing valve, connections for 216 

connections to water accumulator 267 

Pressure regulators (see Pressure-reducing valve) 

Pump and receiver, connections for discharge 
from vacuum pump 149 

Radiator traps (see Return traps) 

valves (see Modulation valves) 
Radiators, indirect, details of connection to ... . 52 
Railroad switch, method of prevention of freez- 
ing 194 

Receiving tanks, plain, method of connecting re- 
turns from vacuum pump 144 

water-control, method of connection to 

vacuum pump and feed-water heater 145 

Reducing valves (see Pressure-reducing valves) 
Regulators, damper (see Damper regulators) 
pressure (see Pressure-reducing valves) 
vacuum (see Vacuum pump governors) 
Returns, dry, methods of connections for modu- 
lation system 228-229 



Returns tank (see Tanks) 

Risers, down-feed, draining through radiator 220, 253 

drainage of 216-219, 224 

method of providing for expansion of 216 

modulation system, methods of draining . 228-229 
used as heating surface 219 

Run-outs, above floor 219 

in floor 218 

under floor 219 

Separating tanks (see Air-separating tank) 

Separators, oil, method of draining 255 

Single-control hydro-pneumatic tanks, connec- 
tions to geared-type vacuum pump 146 

Slasher equipment, typical installation of 189 

Stack, indirect, connections for 225-227 

Steam-control tanks, control of boiler feed 

pump, connections 149 

Steam-driven vacuum pumps, typical connec- 
tions of 150, 166 

Steam mains, drainage of 215 

Steamship piers, fire protection for 195 

Sterilizers (see Hospital equipment) 

Suction strainers, typical connections of 150 

Street system, method of cooling returns from. . 222 
Supply risers (see also Risers) 

drainage by means of heavy-duty trap 223 

Supply valves (see Modulation valves) 
Switches, railroad, method of prevention of 
freezing 194 

Tanks, hydro-pneumatic single-control, connec- 
tions with geared-type vacuum pump 146 

plain air-separating, method of connecting re- 
turns from 144 

steam-control, connections showing boiler- 
feed pump and vacuum pump 149 

water-control, method of connection with vac- 
uum pump and to feed-water heater 145 

Traps (see also Return traps) 

grease and oil, method of connecting for drain- 
ing oU separator 255 

high-pressure Sylphon (see High-pressure Syl- 
phon traps) 

Hylo (see Hylo traps) 

modulation vent (see Modulation vent traps) 

proper location of thermostatic, on lumber dry 
kiln coils 186 

Vacuum governors, typical connections of 151 

pans, appUcation of apparatus 201 

pumps, discharging to automatic pump and 

receiver, connections of 149 

pumps, steam-driven, typical connections 

of 150,166 

regulators (see Vacuum pump governors) 

system, typical layout of 166 

Valves (see also Modulation valves) 
conserving (see Conserving valves) 
modulation vent (see Modulation vent VcJves) 
Vent traps, modulation (see Modulation vent 

traps) 
valves, modulation (see Modulation vent 
valves) 

Ventilating equipment for kitchens 64 

Vento radiation, connections for draining. .. 225-227 

yN&icT accumulators, typical connections to con- 
serving valve 173 

typical connections to pressure-reducing v£ilve.267 

Water-control tanks, method of connection to 
vacuum pump and to feed- water heater 145 



365 



Webster Apparatus 



Accumulator, water {see Water accumulator) 
Air-separating tanks, description and dimensions 

of 264-266 

Anchor points, allowable distance between 283 

Attachments for Sylphon traps (see Trap attach- 
ments) 

Ball check valves (see Modulation vent valves) 
Boiler feeder, description and dimensions of ... . 274 

Check valves, special, for modulation systems, 

application details of 268-269 

Combination gauges 267 

connections for 268 

Conserving valves, description and dimensions 

of. .._. 273 

illustration of 174 

Controllers, Hylo {see Hylo controllers) 

Damper regulators, description and dimensions 
of... 271 

Dirt strainers, description of 259 

dimensions of 260 

Double-control hydro-pneumatic tanks, descrip- 
tion and dimensions of 276-277 

Double-service valves, description of 252-2.54 

dimensions of 254 

ratings of 237 

typical installation detail of 253 

Drag hfts 263 

Economizer, vapor, and suction strainer, des- 
cription and dimensions of 261-262 

Economy table, feed- water heaters 301 

Evaporation, boiler, measurement of 313 

Expansion joints, allowable distances between 

anchor points of 283 

description and dimensions of 278-282 

Feeder, boiler {see Boiler feeder) 

Feed-water heaters, description of 302-313 

dimensions, Webster Class EB 310 

dimensions, Webster Class EBP 311 

dimensions, Webster Class EF 313 

dimensions, Webster Class EFP 312 

economy chart of 301 

typical coimections, steana-control type 304 

typical connections, water-control type 303 

Fittings, Uft {see Lift fittings) 

Fuel saving by preheating feed water 301 

Gauges {see also Combination gauges) 
combination {see Combination gauges) 
typical connections for 150 

Governors, vacuum pump {see also Vacuum pump 
governors) 
typical connections for 151 

Grease traps, description of 257 

dimensions of 258 

method of connection for draining oil sepa- 
rator 255 

Heater-meter, Webster-Lea, description of .313-314 
Heaters, feed-water {see Feed-water heaters) 
Heavy-duty traps, connection for coils drained 

through one trap in lumber dry kilns 187 

high-differential type, description and dimen- 
sions of 249 

method of running return pipe in lumber dry 
kilns 187 



Heavy-duty traps. Series 19T, description of . . . .247 

Series 19T, dimensions of 249 

Series 19T, ratings of 239 

use in lumber-drying kilns 182, 186 

High-differential heavy-duty traps, description 

and dimensions of 249 

High-pressure Sylphon traps, description and 

dimensions of 275 

Hydro-pneumatic tanks, description and dimen- 
sions of 276-277 

selection of .size of 138, 142 

Hylo controllers, dimensions of 272 

Hylo traps, dimensions of 272 

Joints, expansion {see Expansion joints) 

Lift fittings. Series 20, description of 263 

Series 20, dimensions of 264 

typical applications of 263 

Lift pockets {see Lift fittings) 

Lifts, drag 263 

Ivleter-heaters (see Heater-meters) 

Modulation system, typical specification for ... . 289 

valves. Type W, description of 250 

Type W, dimensions of 252 

Type W, ratings of 237 

Type W, with chain attachment, description 

of 252 

Type W, with extended stem 252 

with chain attachment, installation details 

of 251 

vent traps, description and dimensions of .268-270 

typical installation details of 268-269 

vent valves, application details of 268-271 

description and dimensions of 270-271 

Motor valves, attachments for 294 

Muffler oil separators 257 

Multiple-unit valves, attachments for 296 

No. 7 traps, description of 246 

dimensions of 246 

ratings of 238 

Oil separators, allowable velocity through 255 

method of draining by means of grease 

trap 255 

receiver and muffler 257 

Series 21, description of 254 

Series 21, dimensions of 256 

Series 21, ratings of 256 

Plain air-separating tanks, description of 264 

dimensions of 266 

selection of size 138, 142 

Pockets, lift (see Lift fittings) 

Pressure-reducing valves, connections to water 
accumulator 267 

Pressure regulators (see Pressure-reducing valves) 

Pump governors, vacuum, description and di- 
mensions of 260 

Pumps, vacuum, table of sizing 138 

Radiator traps (see Return traps) 
Radiator valves (see Modulation valves) 

Receiver and muffler oil separator 257 

Receiving tanks, description and dimensions 

of 264-266 

selection of size of 138, 142 

Reducing valves, (see Pressinre-reducing valves) 



366 



Index of Webster Apparatus — Continued 



Regulators, damper {see Damper regulators) 
pressure {see Pressure-reducing valves) 
vacuum (see Vacuum pump governors) 

Return traps, method of running return pipe to . 187 

No. 7, description and dimensions of 216 

No. 7, ratings of 237-238 

requirements for perfect operation of 241 

Sylphon, description of 242-245 

Sylphon, ratings of. 237-238 

use for air removal in lumber drv kilns 186 

use in lumber dry kilns '. . . . 182, 18 1-186 

Return tanks {see Tanks) 

Separating tanks- {see Air-separating tanks) 

Separators, oil, allowable velocity through 255 

method of draining 255 

receiver and muHler type 257 

Series 21, description of 254 

Series 21, dimensions of 256 

Series 21, ratings of 256 

Separators, steam. Series 21, description and 
dimensions of 283-285 

Single-control hydro-pneumatic tanks, descrip- 
tion and dimensions of 276-277 

Specifications, typical, modulation system 289 

typical, vacuum system 286 

Steam-control tanks, description of 265 

dimensions of 266 

Steam separators, ratings of 285 

Series 21, description and dimensions of. .283-285 

Strainers, dirt, description of 259 

dirt, dimensions of 260 

suction, and vapor economizer, description and 

dimensions of 261-262 

description of 258 

dimensions of 259 

selection of size of 138, 141 

use of, on lumber dry kiln coils 186 

Suction strainer, and vapor economizer, descrip- 
tion and dimensions of 261-262 

description of 258 

dimensions of 259 

selection of size of 138, 141 

typical connections for 150 

Supply valves {see Modulation valves) 

Sylphon attachments (see Trap attachments) 

Sylphon traps, description of 242-245 

dimensions of 245 

ratings of 237-238 

Tanks, air-separating, description and dimen- 

_ sions of 264-266 

air-separating, selection of size of 138, 141 

Tanks, hydro-pneumatic, description and dimen- 
sions of _ 276-277 

hydro-pneumatic, selection of size of . . . . 138, 142 
plain, selection of size of 138, 142 



Tanks, steam-control, selection of size of. . .138, 142 

water-control, selection of size of 138, 142 

Thermostatic valve No. 4, trap attachments for. 294 

Trap attachments 293 

for motor valves 294 

for multiple-unit valves 296 

for thermo valves 294 

for various types of valves 297 

for wat er-sead-motors 294 

for water-seal traps 295 

Traps (see also Return traps) 

grease and oil, description of 257 

dimensions of 258 

method of connecting for draining oil sepa- 
rator 255 

heavy-duty series 19T, description of 247 

dimensions of 249 

ratings of 239 

high-pressure Sylphon {see High-pressure Syl- 
phon traps) 
Hylo (see Hylo traps) 

modulation vent (see Modulation vent traps) 
proper location of thermostatic type, on lumber 

dry kiln coils 186 

proper type for lumber dry kilns 184 

water-seal, attachments for 295 

vacuum governors, typical connections for .... 151 
pump governors, description and dimensions 

of 260 

regulators {see Vacuum pump governors) 

system, typical specification for 286 

Valves (see also Modulation valves) 
conserving (see Conserving valves) 
modulation vent (see Modulation vent valves) 

radiator outlet, attachments for 297 

Vapor economizer and suction strainer, descrip- 
tion and dimensions of • ■ • . -261 

Velocity, allowable, through oil separators 256 

Vent traps, modulation (see Modulation vent 

traps) 
Vent valves, modulation (see Modulation vent 
valves) 

\A/ Type modulation valves, description of . . . .250 

dimensions of 252 

ratings of 237 

Water accumulators, description and dimensions 

of 267 

typical connections to conserving valve .... 173 
typical connections to pressure-reducing 

valve 267 

-control tank, description of 264 

dimensions of 266 

selection of size of 138, 142 

-seal motors, attachments for 294 

-seal traps, attachments for 295 



367 



WARREN WEBSTER & COMPANY 

EXECUTIVE OFFICES AND WORKS 
CAMDEN, N.J. 



Branch Offices and Representatives 



Atlanta, Ga. 
Atlantic City, N. J. 
Baltimore, Md. 
Birmingham, Ala. 
Boston, Mass. 
Charlotte, N. C. 
Chicago, lU. 
Cincinnati, Ohio 
Cleveland, Ohio 
Colmnbus, Ohio 
Dallas, Texas 
Denver, Colo. 



Detroit, Mich. 
Easton, Pa. 
Grand Rapids, Mich. 
Houston, Texas 
IndianapoUs, Ind. 
Kansas City, Mo. 
Los Angeles, Cal. 
Memphis, Tenn. 
Milwaukee, Wis. 
Minneapolis, Minn. 
New Orleans, La. 
New York, N. Y. 
Omaha, Neb. 



Philadelphia, Pa. 
Pittsburgh, Pa. 
Portland, Ore. 
Rochester, N. Y. 
Saginaw, Mich. 
San Francisco, Cal. 
Seattle, Wash. 
St. Louis, Mo. 
Syracuse, N. Y. 
Toledo, Ohio 
Washington, D. C. 
Wilkes-Barre, Pa. 



Sole Representatives and Manufacturers in Canada 

DARLING BROTHERS, Limited 
Head Office and Works, Montreal, P. Q. 

Branch Offices and Representatives 

Calgary Ottawa Quebec Vancouver 

Halifax Toronto Winnipeg 



London, England 
THE ATMOSPHERIC STEAM HEATING CO., Ltd. 



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